理解ICS Surface和SurfaceFlinger的处理流程
ISurfaceComposer接口的实现类：
------------------------------------------------------------------
接口ISurfaceComposerClient
->BnSurfaceComposerClient
->
实现类Client，位于SurfaceFlinger.h文件中
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接口ISurfaceComposer
->
BnSurfaceComposer
->
实现类SurfaceFlinger
ISurfaceComposer类含有以下成员函数，用于与SurfaceFlinger建立联系
/* create connection with surface flinger, requires
* ACCESS_SURFACE_FLINGER permission
*/
virtual sp<ISurfaceComposerClient> createConnection() = 0;
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1.SurfaceComposerClient类含有接口ISurfaceComposerClient类型的成员变量mClient
2.SurfaceControl类含有SurfaceComposerClient类型的成员变量mClient
3.SurfaceComposerClient::createSurface函数，返回值类型为SurfaceControl
（1）调用成员mClient的createSurface函数创建Surface
mClient->createSurface实际是调用的接口ISurfaceComposerClient的实现类Client
（2）创建SurfaceControl对象，管理（1）中创建的Surface
（3）返回（2）中创建的SurfaceControl对象
4.SurfaceComposerClient对象的创建
创建SurfaceComposerClient对象的地方位于jni中，对应的文件是android_view_Surface.cpp，函数是SurfaceSession_init，
对应与java类SurfaceSession中的init函数。
{"init", "()V", (void*)SurfaceSession_init },
未完待续……