HWUI debug method

1.frameworks/base/libs/hwui$ vim ./Properties.h +141

/**

 * Controls whether or not HWUI will use the EGL_EXT_buffer_age extension
 * to do partial invalidates. Setting this to "false" will fall back to
 * using BUFFER_PRESERVED instead
 * Default is "true"
 */
#define PROPERTY_USE_BUFFER_AGE "debug.hwui.use_buffer_age"

/**
 * Setting this to "false" will force HWUI to always do full-redraws of the surface.
 * This will disable the use of EGL_EXT_buffer_age and BUFFER_PRESERVED.
 * Default is "true"
 */
#define PROPERTY_ENABLE_PARTIAL_UPDATES "debug.hwui.use_partial_updates"

2.hwui disable 

   private static final String PROPERTY_DISABLE_HWACC = "debug.disable.hwacc";

3.frameworks/base/libs/hwui/renderthread/CanvasContext.cpp

void CanvasContext::draw() {

4.HWUI goole offical patch

https://android.googlesource.com/platform/frameworks/base/+/1deac99c557d4be757c266e066a0d614c1959474