Puppeteer开发过程中遇到的问题及解决方案

工欲善其事必先利其器，请先检查本机是否安装NodeJS环境以及查阅API：

Google官方文档：https://developers.google.com/web/tools/puppeteer

API（v12.0.1）文档：https://pptr.dev/#?product=Puppeteer&version=v12.0.1&show=outline

问题：如何处理各种验证码？

解决方案：建议大家去搜索对应的解决方案，Puppeteer并无此类解决方案。

问题：某些网站做了JS防爬检测，如何解决？

解决方案：如果想要详细了解请点击（或者点击跳转，文章末有相关参考说明）：List of Chromium Command Line Switches ? Peter Beverloo

注意事项：Chrome添加ignoreDefaultArgs: ["--enable-automation"]无效，请自行测试
const optionsLaunch = {
    headless: false,
    devtools: false,
    defaultViewport: {
        width: 1200,
        height: 900
    },
    slowMo: 250,
    timeout: 0,
    // product: "chrome",
    ignoreHTTPSErrors: true,
    ignoreDefaultArgs: ["--enable-automation"],
    // channel: "chrome",
    // executablePath: "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome"
};

问题：异常之后如何处理？

解决方案：我这边个人一般是当遇见异常中，退出当前浏览器，重新创建一个新的即可。

Condition	Explanation
--/prefetch:1[1] ?	/prefetch:# arguments to use when launching various process types. It has been observed that when file reads are consistent for 3 process launches with the same /prefetch:# argument, the Windows prefetcher starts issuing reads in batch at process launch. Because reads depend on the process type, the prefetcher wouldn't be able to observe consistent reads if no /prefetch:# arguments were used. Note that the browser process has no /prefetch:# argument; as such all other processes must have one in order to avoid polluting its profile. Note: # must always be in [1, 8]; otherwise it is ignored by the Windows prefetcher. ?
--/prefetch:2[1] ?	No description ?
--/prefetch:3[1] ?	No description ?
--/prefetch:4[1] ?	No description ?
--/prefetch:5[1] ?	/prefetch:# arguments for the browser process launched in background mode and for the watcher process. Use profiles 5, 6 and 7 as documented on kPrefetchArgument* in content_switches.cc. ?
--/prefetch:6[1] ?	No description ?
--/prefetch:8[1] ?	Prefetch arguments are used by the Windows prefetcher to disambiguate different execution modes (i.e. process types) of the same executable image so that different types of processes don't trample each others' prefetch behavior. Legal values are integers in the range [1, 8]. We reserve 8 to mean "whatever", and this will ultimately lead to processes with /prefetch:8 having inconsistent behavior thus disabling prefetch in practice. TODO(rockot): Make it possible for embedders to override this argument on a per-service basis. ?
--10000 ?	No description ?
--100000 ?	No description ?
--1000000 ?	No description ?
--3d-display-mode[1] ?	No description ?
--50000 ?	No description ?
--500000 ?	No description ?
--5000000 ?	No description ?
--? ?	No description ?
--accept-resource-provider ?	Flag indicating that a resource provider must be set up to provide cast receiver with resources. Apps cannot start until provided resources. This flag implies --alsa-check-close-timeout=0. ?
--adaboost ?	No description ?
--add-gpu-appcontainer-caps[1] ?	Add additional capabilities to the AppContainer sandbox on the GPU process. ?
--add-xr-appcontainer-caps[1] ?	Add additional capabilities to the AppContainer sandbox used for XR compositing. ?
--additional-trust-token-key-commitments ?	Manually sets additional Trust Tokens key commitments in the network service to the given value, which should be a JSON dictionary satisfying the requirements of TrustTokenKeyCommitmentParser::ParseMultipleIssuers. These keys are available in addition to keys provided by the most recent call to TrustTokenKeyCommitments::Set. For issuers with keys provided through both the command line and TrustTokenKeyCommitments::Set, the keys provided through the command line take precedence. This is because someone testing manually might want to pass additional keys via the command line to a real Chrome release with the component updater enabled, and it would be surprising if the manually-passed keys were overwritten some time after startup when the component updater runs. ?
--agc-startup-min-volume ?	Override the default minimum starting volume of the Automatic Gain Control algorithm in WebRTC used with audio tracks from getUserMedia. The valid range is 12-255. Values outside that range will be clamped to the lowest or highest valid value inside WebRTC. TODO(tommi): Remove this switch when crbug.com/555577 is fixed. ?
--aggressive ?	No description ?
--aggressive-cache-discard ?	No description ?
--aggressive-tab-discard ?	No description ?
--all ?	No description ?
--all-renderers ?	No description ?
--allarticles ?	No description ?
--allow-cross-origin-auth-prompt ?	Allows third-party content included on a page to prompt for a HTTP basic auth username/password pair. ?
--allow-external-pages ?	Allow access to external pages during web tests. ?
--allow-failed-policy-fetch-for-test ?	If this flag is passed, failed policy fetches will not cause profile initialization to fail. This is useful for tests because it means that tests don't have to mock out the policy infrastructure. ?
--allow-file-access-from-files ?	By default, file:// URIs cannot read other file:// URIs. This is an override for developers who need the old behavior for testing. ?
--allow-http-background-page ?	Allows non-https URL for background_page for hosted apps. ?
--allow-http-screen-capture ?	Allow non-secure origins to use the screen capture API and the desktopCapture extension API. ?
--allow-insecure-localhost ?	Enables TLS/SSL errors on localhost to be ignored (no interstitial, no blocking of requests). ?
--allow-legacy-extension-manifests ?	Allows the browser to load extensions that lack a modern manifest when that would otherwise be forbidden. ?
--allow-loopback-in-peer-connection ?	Allows loopback interface to be added in network list for peer connection. ?
--allow-nacl-crxfs-api[2] ?	Specifies comma-separated list of extension ids or hosts to grant access to CRX file system APIs. ?
--allow-nacl-file-handle-api[2] ?	Specifies comma-separated list of extension ids or hosts to grant access to file handle APIs. ?
--allow-nacl-socket-api[2] ?	Specifies comma-separated list of extension ids or hosts to grant access to TCP/UDP socket APIs. ?
--allow-no-sandbox-job ?	Enables the sandboxed processes to run without a job object assigned to them. This flag is required to allow Chrome to run in RemoteApps or Citrix. This flag can reduce the security of the sandboxed processes and allow them to do certain API calls like shut down Windows or access the clipboard. Also we lose the chance to kill some processes until the outer job that owns them finishes. ?
--allow-outdated-plugins ?	Don't block outdated plugins. ?
--allow-popups-during-page-unload ?	Allow a page to show popups during its unloading. TODO(https://crbug.com/937569): Remove this in Chrome 88. ?
--allow-pre-commit-input ?	Allows processing of input before a frame has been committed. TODO(schenney): crbug.com/987626. Used by headless. Look for a way not involving a command line switch. ?
--allow-profiles-outside-user-dir ?	Allows profiles to be created outside of the user data dir. TODO(https://crbug.com/1060366): Various places in Chrome assume that all profiles are within the user data dir. Some tests need to violate that assumption. The switch should be removed after this workaround is no longer needed. ?
--allow-ra-in-dev-mode ?	Allows remote attestation (RA) in dev mode for testing purpose. Usually RA is disabled in dev mode because it will always fail. However, there are cases in testing where we do want to go through the permission flow even in dev mode. This can be enabled by this flag. ?
--allow-running-insecure-content ?	No description ?
--allow-sandbox-debugging ?	Allows debugging of sandboxed processes (see zygote_main_linux.cc). ?
--allow-silent-push ?	Allows Web Push notifications that do not show a notification. ?
--allow-sync-xhr-in-page-dimissal ?	Allow a page to send synchronus XHR during its unloading. TODO(https://crbug.com/1003101): Remove this in Chrome 88. ?
--allow-third-party-modules[1] ?	Allows third party modules to inject by disabling the BINARY_SIGNATURE mitigation policy on Win10+. Also has other effects in ELF. ?
--allow-unsecure-dlls[3] ?	Don't allow EnableSecureDllLoading to run when this is set. This is only to be used in tests. ?
--alsa-amp-device-name ?	Name of the device the amp mixer should be opened on. If this flag is not specified it will default to the same device as kAlsaVolumeDeviceName. ?
--alsa-amp-element-name ?	Name of the simple mixer control element that the ALSA-based media library should use to toggle powersave mode on the system. ?
--alsa-check-close-timeout ?	Time in ms to wait before closing the PCM handle when no more mixer inputs remain. Assumed to be 0 if --accept-resource-provider is present. ?
--alsa-enable-upsampling ?	Flag that enables resampling audio with sample rate below 32kHz up to 48kHz. Should be set to true for internal audio products. ?
--alsa-fixed-output-sample-rate ?	Optional flag to set a fixed sample rate for the alsa device. Deprecated: Use --audio-output-sample-rate instead. ?
--alsa-input-device[4] ?	The Alsa device to use when opening an audio input stream. ?
--alsa-mute-device-name ?	Name of the device the mute mixer should be opened on. If this flag is not specified it will default to the same device as kAlsaVolumeDeviceName. ?
--alsa-mute-element-name ?	Name of the simple mixer control element that the ALSA-based media library should use to mute the system. ?
--alsa-output-avail-min ?	Minimum number of available frames for scheduling a transfer. ?
--alsa-output-buffer-size ?	Size of the ALSA output buffer in frames. This directly sets the latency of the output device. Latency can be calculated by multiplying the sample rate by the output buffer size. ?
--alsa-output-device[4] ?	The Alsa device to use when opening an audio stream. ?
--alsa-output-period-size ?	Size of the ALSA output period in frames. The period of an ALSA output device determines how many frames elapse between hardware interrupts. ?
--alsa-output-start-threshold ?	How many frames need to be in the output buffer before output starts. ?
--alsa-volume-device-name ?	Name of the device the volume control mixer should be opened on. Will use the same device as kAlsaOutputDevice and fall back to "default" if kAlsaOutputDevice is not supplied. ?
--alsa-volume-element-name ?	Name of the simple mixer control element that the ALSA-based media library should use to control the volume. ?
--also-emit-success-logs ?	Also emit full event trace logs for successful tests. ?
--alt1 ?	The Chrome-Proxy "exp" directive value used by data reduction proxy to receive an alternative back end implementation. ?
--alt10 ?	No description ?
--alt2 ?	No description ?
--alt3 ?	No description ?
--alt4 ?	No description ?
--alt5 ?	No description ?
--alt6 ?	No description ?
--alt7 ?	No description ?
--alt8 ?	No description ?
--alt9 ?	No description ?
--always-use-complex-text ?	Always use the complex text path for web tests. ?
--alwaystrue ?	No description ?
--android-fonts-path ?	Uses the android SkFontManager on linux. The specified directory should include the configuration xml file with the name "fonts.xml". This is used in blimp to emulate android fonts on linux. ?
--angle ?	No description ?
--animation-duration-scale ?	Scale factor to apply to every animation duration. Must be >= 0.0. This will only apply to LinearAnimation and its subclasses. ?
--app ?	Specifies that the associated value should be launched in "application" mode. ?
--app-auto-launched ?	Specifies whether an app launched in kiosk mode was auto launched with zero delay. Used in order to properly restore auto-launched state during session restore flow. ?
--app-cache-force-enabled ?	Allows app cache to be forced on, even when gated by an origin trial. TODO(enne): remove this once app cache has been removed. ?
--app-id ?	Specifies that the extension-app with the specified id should be launched according to its configuration. ?
--app-launch-url-for-shortcuts-menu-item ?	Overrides the launch url of an app with the specified url. This is used along with kAppId to launch a given app with the url corresponding to an item in the app's shortcuts menu. ?
--app-mode-auth-code ?	Value of GAIA auth code for --force-app-mode. ?
--app-mode-oauth-token ?	Value of OAuth2 refresh token for --force-app-mode. ?
--app-mode-oem-manifest ?	Path for app's OEM manifest file. ?
--app-shell-allow-roaming[5] ?	Allow roaming in the cellular network. ?
--app-shell-host-window-size[5] ?	Size for the host window to create (i.e. "800x600"). ?
--app-shell-preferred-network[5] ?	SSID of the preferred WiFi network. ?
--apple ?	No description ?
--apps-gallery-download-url ?	The URL that the webstore APIs download extensions from. Note: the URL must contain one '%s' for the extension ID. ?
--apps-gallery-update-url ?	The update url used by gallery/webstore extensions. ?
--apps-gallery-url ?	The URL to use for the gallery link in the app launcher. ?
--apps-keep-chrome-alive-in-tests[6] ?	Prevents Chrome from quitting when Chrome Apps are open. ?
--arc-availability ?	Signals ARC support status on this device. This can take one of the following three values. - none: ARC is not installed on this device. (default) - installed: ARC is installed on this device, but not officially supported. Users can enable ARC only when Finch experiment is turned on. - officially-supported: ARC is installed and supported on this device. So users can enable ARC via settings etc. ?
--arc-available ?	DEPRECATED: Please use --arc-availability=installed. Signals the availability of the ARC instance on this device. ?
--arc-build-properties ?	A JSON dictionary whose content is the same as cros config's /arc/build-properties. ?
--arc-data-cleanup-on-start ?	Flag that forces ARC data be cleaned on each start. ?
--arc-disable-app-sync ?	Flag that disables ARC app sync flow that installs some apps silently. Used in autotests to resolve racy conditions. ?
--arc-disable-gms-core-cache ?	Used in autotest to disable GMS-core caches which is on by default. ?
--arc-disable-locale-sync ?	Flag that disables ARC locale sync with Android container. Used in autotest to prevent conditions when certain apps, including Play Store may get restarted. Restarting Play Store may cause random test failures. Enabling this flag would also forces ARC container to use 'en-US' as a locale and 'en-US,en' as preferred languages. ?
--arc-disable-play-auto-install ?	Flag that disables ARC Play Auto Install flow that installs set of predefined apps silently. Used in autotests to resolve racy conditions. ?
--arc-disable-system-default-apps ?	Used for development of Android app that are included into ARC++ as system default apps in order to be able to install them via adb. ?
--arc-enable-native-bridge-64bit-support-experiment ?	Flag to enables an experiment to allow users to turn on 64-bit support in native bridge on systems that have such support available but not yet enabled by default. ?
--arc-force-cache-app-icons ?	Flag that forces ARC to cache icons for apps. ?
--arc-force-show-optin-ui ?	Flag that forces the OptIn ui to be shown. Used in tests. ?
--arc-packages-cache-mode ?	Used in autotest to specifies how to handle packages cache. Can be copy - copy resulting packages.xml to the temporary directory. skip-copy - skip initial packages cache setup and copy resulting packages.xml to the temporary directory. ?
--arc-play-store-auto-update ?	Used in autotest to forces Play Store auto-update state. Can be on - auto-update is forced on. off - auto-update is forced off. ?
--arc-scale ?	Set the scale for ARC apps. This is in DPI. e.g. 280 DPI is ~ 1.75 device scale factor. See https://source.android.com/compatibility/android-cdd#3_7_runtime_compatibility for list of supported DPI values. ?
--arc-start-mode ?	Defines how to start ARC. This can take one of the following values: - always-start automatically start with Play Store UI support. - always-start-with-no-play-store automatically start without Play Store UI. If it is not set, then ARC is started in default mode. ?
--arc-tos-host-for-tests ?	Sets ARC Terms Of Service hostname url for testing. ?
--arc-transition-migration-required ?	If this flag is present then the device had ARC M available and gets ARC N when updating. TODO(pmarko): Remove this when we assess that it's not necessary anymore: crbug.com/761348. ?
--as-browser ?	Flag to launch tests in the browser process. ?
--ash-color-mode ?	Indicates the current color mode of ash. ?
--ash-constrain-pointer-to-root ?	Force the pointer (cursor) position to be kept inside root windows. ?
--ash-contextual-nudges-interval ?	Overrides the minimum time that must pass between showing user contextual nudges. Unit of time is in seconds. ?
--ash-contextual-nudges-reset-shown-count ?	Reset contextual nudge shown count on login. ?
--ash-debug-shortcuts ?	Enable keyboard shortcuts useful for debugging. ?
--ash-dev-shortcuts ?	Enable keyboard shortcuts used by developers only. ?
--ash-disable-touch-exploration-mode ?	Disable the Touch Exploration Mode. Touch Exploration Mode will no longer be turned on automatically when spoken feedback is enabled when this flag is set. ?
--ash-enable-cursor-motion-blur ?	Enable cursor motion blur. ?
--ash-enable-magnifier-key-scroller ?	Enables key bindings to scroll magnified screen. ?
--ash-enable-palette-on-all-displays ?	Enables the palette on every display, instead of only the internal one. ?
--ash-enable-software-mirroring ?	Enables software based mirroring. ?
--ash-enable-unified-desktop[5] ?	Enables unified desktop mode. ?
--ash-enable-v1-app-back-button ?	Enables Backbutton on frame for v1 apps. TODO(oshima): Remove this once the feature is launched. crbug.com/749713. ?
--ash-hide-notifications-for-factory ?	Hides notifications that are irrelevant to Chrome OS device factory testing, such as battery level updates. ?
--ash-host-window-bounds ?	Sets a window size, optional position, and optional scale factor. "1024x768" creates a window of size 1024x768. "100+200-1024x768" positions the window at 100,200. "1024x768*2" sets the scale factor to 2 for a high DPI display. "800,0+800-800x800" for two displays at 800x800 resolution. "800,0+800-800x800,0+1600-800x800" for three displays at 800x800 resolution. ?
--ash-power-button-position ?	Power button position includes the power button's physical display side and the percentage for power button center position to the display's width/height in landscape_primary screen orientation. The value is a JSON object containing a "position" property with the value "left", "right", "top", or "bottom". For "left" and "right", a "y" property specifies the button's center position as a fraction of the display's height (in [0.0, 1.0]) relative to the top of the display. For "top" and "bottom", an "x" property gives the position as a fraction of the display's width relative to the left side of the display. ?
--ash-side-volume-button-position ?	The physical position info of the side volume button while in landscape primary screen orientation. The value is a JSON object containing a "region" property with the value "keyboard", "screen" and a "side" property with the value "left", "right", "top", "bottom". ?
--ash-touch-hud ?	Enables the heads-up display for tracking touch points. ?
--attestation-server ?	Used in CryptohomeClient to determine which Google Privacy CA to use for attestation. ?
--audio ?	No description ?
--audio-buffer-size ?	Allow users to specify a custom buffer size for debugging purpose. ?
--audio-output-channels ?	Number of audio output channels. This will be used to send audio buffer with specific number of channels to ALSA and generate loopback audio. Default value is 2. ?
--audio-output-sample-rate ?	Specify fixed sample rate for audio output stream. If this flag is not specified the StreamMixer will choose sample rate based on the sample rate of the media stream. ?
--audio-service-quit-timeout-ms ?	Set a timeout (in milliseconds) for the audio service to quit if there are no client connections to it. If the value is negative the service never quits. ?
--aue-reached-for-update-required-test ?	If this switch is passed, the device policy DeviceMinimumVersion assumes that the device has reached Auto Update Expiration. This is useful for testing the policy behaviour on the DUT. ?
--aura-legacy-power-button ?	(Most) Chrome OS hardware reports ACPI power button releases correctly. Standard hardware reports releases immediately after presses. If set, we lock the screen or shutdown the system immediately in response to a press instead of displaying an interactive animation. ?
--auth-server-whitelist ?	Allowlist for Negotiate Auth servers. ?
--auth-spnego-account-type[7] ?	Android authentication account type for SPNEGO authentication ?
--auto ?	No description ?
--auto-open-devtools-for-tabs ?	This flag makes Chrome auto-open DevTools window for each tab. It is intended to be used by developers and automation to not require user interaction for opening DevTools. ?
--auto-select-desktop-capture-source ?	This flag makes Chrome auto-select the provided choice when an extension asks permission to start desktop capture. Should only be used for tests. For instance, --auto-select-desktop-capture-source="Entire screen" will automatically select sharing the entire screen in English locales. The switch value only needs to be substring of the capture source name, i.e. "display" would match "Built-in display" and "External display", whichever comes first. ?
--autofill-api-key ?	Sets the API key that will be used when calling Autofill API instead of using Chrome's baked key by default. You can use this to test new versions of the API that are not linked to the Chrome baked key yet. ?
--autofill-assistant-auth ?	Disables authentication when set to false. This is only useful during development, as prod instances require authentication. ?
--autofill-assistant-key ?	Sets the API key to be used instead of Chrome's default key when sending requests to the backend. ?
--autofill-assistant-url ?	Overrides the default backend URL. ?
--autofill-ios-delay-between-fields ?	The delay between filling two fields. ?
--autofill-metadata-upload-encoding ?	The randomized encoding type to use when sending metadata uploads. The value of the parameter must be one of the valid integer values of the AutofillRandomizedValue_EncodingType enum. ?
--autofill-server-url ?	Override the default autofill server URL with "scheme://host[:port]/prefix/". ?
--autofill-upload-throttling-period-in-days ?	The number of days after which to reset the registry of autofill events for which an upload has been sent. ?
--autoplay-policy ?	Command line flag name to set the autoplay policy. ?
--autopush ?	The command line alias and URL for the "autopush" environment. ?
--back-gesture-horizontal-threshold ?	The number of pixels from the start of a left swipe gesture to consider as a 'back' gesture. ?
--blink-settings ?	Set blink settings. Format is [=[=],... The names are declared in Settings.json5. For boolean type, use "true", "false", or omit '=' part to set to true. For enum type, use the int value of the enum value. Applied after other command line flags and prefs. ?
--block-new-web-contents ?	If true, then all pop-ups and calls to window.open will fail. ?
--bootstrap ?	Values for the kExtensionContentVerification flag. See ContentVerifierDelegate::Mode for more explanation. ?
--bottom-gesture-start-height ?	The number of pixels up from the bottom of the screen to consider as a valid origin for a bottom swipe gesture. If set, overrides the value of both the above system-gesture-start-height flag and the default value in cast_system_gesture_handler.cc. ?
--browser ?	No description ?
--browser-startup-dialog ?	Causes the browser process to display a dialog on launch. ?
--browser-subprocess-path ?	Path to the exe to run for the renderer and plugin subprocesses. ?
--browser-test ?	Tells whether the code is running browser tests (this changes the startup URL used by the content shell and also disables features that can make tests flaky [like monitoring of memory pressure]). ?
--bwsi ?	Indicates that the browser is in "browse without sign-in" (Guest session) mode. Should completely disable extensions, sync and bookmarks. ?
--bypass-app-banner-engagement-checks ?	This flag causes the user engagement checks for showing app banners to be bypassed. It is intended to be used by developers who wish to test that their sites otherwise meet the criteria needed to show app banners. ?
--cast-app-background-color ?	Background color used when Chromium hasn't rendered anything yet. ?
--cast-initial-screen-height ?	No description ?
--cast-initial-screen-width ?	Used to pass initial screen resolution to GPU process. This allows us to set screen size correctly (so no need to resize when first window is created). ?
--cc-layer-tree-test-long-timeout ?	Increases timeout for memory checkers. ?
--cc-layer-tree-test-no-timeout ?	Prevents the layer tree unit tests from timing out. ?
--cc-scroll-animation-duration-in-seconds ?	Controls the duration of the scroll animation curve. ?
--cdm ?	No description ?
--cellular-first ?	If this flag is set, it indicates that this device is a "Cellular First" device. Cellular First devices use cellular telephone data networks as their primary means of connecting to the internet. Setting this flag has two consequences: 1. Cellular data roaming will be enabled by default. 2. UpdateEngine will be instructed to allow auto-updating over cellular data connections. ?
--check-accessibility-permission[8] ?	No description ?
--check-damage-early ?	Checks damage early and aborts the frame if no damage, so that clients like Android WebView don't invalidate unnecessarily. ?
--check-for-update-interval ?	How often (in seconds) to check for updates. Should only be used for testing purposes. ?
--check-permission[8] ?	No description ?
--check-screen-recording-permission[8] ?	No description ?
--child-wallpaper-large ?	Default large wallpaper to use for kids accounts (as path to trusted, non-user-writable JPEG file). ?
--child-wallpaper-small ?	Default small wallpaper to use for kids accounts (as path to trusted, non-user-writable JPEG file). ?
--chrome-mojo-pipe-token ?	The Mojo pipe token for IPC communication between the Software Reporter and Chrome. Dropped in M80. ?
--ChromeOSMemoryPressureHandling ?	The memory pressure thresholds selection which is used to decide whether and when a memory pressure event needs to get fired. ?
--cipher-suite-blacklist ?	Comma-separated list of SSL cipher suites to disable. ?
--clamshell ?	Values for the kAshUiMode flag. ?
--class[9] ?	The same as the --class argument in X applications. Overrides the WM_CLASS window property with the given value. ?
--cleaning-timeout ?	Set the timeout for the cleaning phase, in minutes. 0 disables the timeout entirely. WARNING: this switch is used by internal test systems. Be careful when making changes. ?
--cleanup-id ?	Identifier used to group all reports generated during the same run of the cleaner, including runs before and after a reboot. The id is generated by the first cleaner process for a run, and propagated to spawned or scheduled cleaner processes. A new id will be generated in the first process for a subsequent cleanup, so cleanups from the same user cannot be tracked over time. ?
--clear-key-cdm-path-for-testing ?	Specifies the path to the Clear Key CDM for testing, which is necessary to support External Clear Key key system when library CDM is enabled. Note that External Clear Key key system support is also controlled by feature kExternalClearKeyForTesting. ?
--clear-token-service ?	Clears the token service before using it. This allows simulating the expiration of credentials during testing. ?
--cloud-print-file ?	Tells chrome to display the cloud print dialog and upload the specified file for printing. ?
--cloud-print-file-type ?	Specifies the mime type to be used when uploading data from the file referenced by cloud-print-file. Defaults to "application/pdf" if unspecified. ?
--cloud-print-job-title ?	Used with kCloudPrintFile to specify a title for the resulting print job. ?
--cloud-print-print-ticket ?	Used with kCloudPrintFile to specify a JSON print ticket for the resulting print job. Defaults to null if unspecified. ?
--cloud-print-setup-proxy ?	Setup cloud print proxy for provided printers. This does not start service or register proxy for autostart. ?
--cloud-print-url ?	The URL of the cloud print service to use, overrides any value stored in preferences, and the default. Only used if the cloud print service has been enabled. Used for testing. ?
--cloud-print-xmpp-endpoint ?	The XMPP endpoint the cloud print service will use. Only used if the cloud print service has been enabled. Used for testing. ?
--compensate-for-unstable-pinch-zoom ?	Enable compensation for unstable pinch zoom. Some touch screens display significant amount of wobble when moving a finger in a straight line. This makes two finger scroll trigger an oscillating pinch zoom. See crbug.com/394380 for details. ?
--compile-shader-always-succeeds ?	Always return success when compiling a shader. Linking will still fail. ?
--component-updater ?	Comma-separated options to troubleshoot the component updater. Only valid for the browser process. ?
--connectivity-check-url ?	Url for network connectivity checking. Default is "https://clients3.google.com/generate_204". ?
--conservative ?	No description ?
--content-directories ?	No description ?
--content-shell-hide-toolbar ?	Hides toolbar from content_shell's host window. ?
--content-shell-host-window-size ?	Size for the content_shell's host window (i.e. "800x600"). ?
--controller ?	No description ?
--conversions-debug-mode ?	Causes the Conversion Measurement API to run without delays or noise. ?
--copy-to-download-dir ?	Copy user action data to download directory. ?
--cors-exempt-headers ?	No description ?
--crash ?	Crash flag to force a crash right away. Mainly intended for ensuring crashes are properly recorded by crashpad. ?
--crash-dumps-dir ?	The directory breakpad should store minidumps in. ?
--crash-handler ?	Runs as the Crashpad handler. ?
--crash-loop-before[5] ?	A time_t. Passed by session_manager into the Chrome user session, indicating that if Chrome crashes before the indicated time, session_manager will consider this to be a crash-loop situation and log the user out. Chrome mostly just passes this to crash_reporter if it crashes. ?
--crash-on-failure ?	When specified to "enable-leak-detection" command-line option, causes the leak detector to cause immediate crash when found leak. ?
--crash-on-hang-threads ?	Comma-separated list of BrowserThreads that cause browser process to crash if the given browser thread is not responsive. UI/IO are the BrowserThreads that are supported. For example: --crash-on-hang-threads=UI:18,IO:18 --> Crash the browser if UI or IO is not responsive for 18 seconds while the other browser thread is responsive. ?
--crash-server-url ?	Server url to upload crash data to. Default is "https://clients2.google.com/cr/report" for prod devices. Default is "https://clients2.google.com/cr/staging_report" for non prod. ?
--crash-test ?	Causes the browser process to crash on startup. ?
--crashpad-handler ?	A process type (switches::kProcessType) that indicates chrome.exe or setup.exe is being launched as crashpad_handler. This is only used on Windows. We bundle the handler into chrome.exe on Windows because there is high probability of a "new" .exe being blocked or interfered with by application firewalls, AV software, etc. On other platforms, crashpad_handler is a standalone executable. ?
--crashpad-handler-pid[10] ?	The process ID of the Crashpad handler. ?
--create-browser-on-startup-for-tests ?	Some platforms like ChromeOS default to empty desktop. Browser tests may need to add this switch so that at least one browser instance is created on startup. TODO(nkostylev): Investigate if this switch could be removed. (http://crbug.com/148675) ?
--cros-region ?	Forces CrOS region value. ?
--cros-regions-mode ?	Control regions data load ("" is default). ?
--crosh-command[5] ?	Custom crosh command. ?
--cryptauth-http-host ?	Overrides the default URL for Google APIs (https://www.googleapis.com) used by CryptAuth. ?
--cryptauth-v2-devicesync-http-host ?	Overrides the default URL for CryptAuth v2 DeviceSync: https://cryptauthdevicesync.googleapis.com. ?
--cryptauth-v2-enrollment-http-host ?	Overrides the default URL for CryptAuth v2 Enrollment: https://cryptauthenrollment.googleapis.com. ?
--custom-android-messages-domain ?	No description ?
--custom-devtools-frontend ?	Specifies the http:// endpoint which will be used to serve devtools://devtools/custom/ Or a file:// URL to specify a custom file path to load from for devtools://devtools/bundled/ ?
--custom-launcher-page ?	Specifies the chrome-extension:// URL for the contents of an additional page added to the app launcher. ?
--custom_summary[7] ?	Forces a custom summary to be displayed below the update menu item. ?
--d3d-support[1] ?	No description ?
--d3d11 ?	No description ?
--d3d11-null ?	Special switches for "NULL"/stub driver implementations. ?
--d3d11on12 ?	No description ?
--d3d9 ?	No description ?
--daemon ?	No description ?
--dark ?	No description ?
--data-path ?	Makes Content Shell use the given path for its data directory. ?
--data-reduction-proxy-client-config ?	Uses the encoded ClientConfig instead of fetching one from the config server. This value is always used, regardless of error or expiration. The value should be a base64 encoded binary protobuf. ?
--data-reduction-proxy-config-url ?	The URL from which to retrieve the Data Reduction Proxy configuration. ?
--data-reduction-proxy-experiment ?	The name of a Data Reduction Proxy experiment to run. These experiments are defined by the proxy server. Use --force-fieldtrials for Data Reduction Proxy field trials. ?
--data-reduction-proxy-http-proxies ?	The semicolon-separated list of proxy server URIs to override the list of HTTP proxies returned by the Data Saver API. It is illegal to use |kDataReductionProxy| or |kDataReductionProxyFallback| switch in conjunction with |kDataReductionProxyHttpProxies|. If the URI omits a scheme, then the proxy server scheme defaults to HTTP, and if the port is omitted then the default port for that scheme is used. E.g. "http://foo.net:80", "http://foo.net", "foo.net:80", and "foo.net" are all equivalent. ?
--data-reduction-proxy-pingback-url ?	No description ?
--data-reduction-proxy-secure-proxy-check-url ?	Sets a secure proxy check URL to test before committing to using the Data Reduction Proxy. Note this check does not go through the Data Reduction Proxy. ?
--data-reduction-proxy-server-experiments-disabled ?	Disables server experiments that may be enabled through field trial. ?
--dbus-stub ?	Forces the stub implementation of D-Bus clients. ?
--de-jelly-screen-width ?	Screen width is useful for debugging. Shipping implementations should detect this. ?
--deadline-to-synchronize-surfaces ?	The default number of the BeginFrames to wait to activate a surface with dependencies. ?
--debug-devtools ?	Run devtools tests in debug mode (not bundled and minified) ?
--debug-enable-frame-toggle ?	Enables a frame context menu item that toggles the frame in and out of glass mode (Windows Vista and up only). ?
--debug-packed-apps ?	Adds debugging entries such as Inspect Element to context menus of packed apps. ?
--debug-print[11] ?	Enables support to debug printing subsystem. ?
--default ?	No description ?
--default-background-color ?	The background color to be used if the page doesn't specify one. Provided as RGBA integer value in hex, e.g. 'ff0000ff' for red or '00000000' for transparent. ?
--default-country-code[7] ?	Default country code to be used for search engine localization. ?
--default-tile-height ?	No description ?
--default-tile-width ?	Sets the tile size used by composited layers. ?
--default-wallpaper-is-oem ?	Indicates that the wallpaper images specified by kAshDefaultW