ActivityManagerNative.getDefault().startActivity()
Activity.startActivityFraomFragment()
ContextImpl appContext = createBaseContextForActivity(r);
ActivityThread.handleLaunchActivity()
Instrumentation.execStartActivity()
ApplicationThreadNative.onTransact()
Binder
ActivityManagerService.startActivityAsUser()
ActivityManagerService.onTransact()(因为AMS继承AMN)
ActivityThread.performLaunchActivity()
其中的packageInfo是LoadedAPK对象
Application app = r.packageInfo.makeApplication(...)
ApplicationThread.scheduleLaunchActivity
Instrumentation.newActivity()
activity = mInstrumentation.newActivity(..)
mBase.startActivity()其实是ContextImpl.startActivity()
mInstrumentation.callActivityOnRestoreInstanceState(...)
ActivityThread.performLaunchActivity()方法分析，下面列出其重点流程调用
Application.startActivity()
ActivityStackSupervisor.realStartActivityLocked()
...
mInstrumentation.callActivityOnPostCreate()
Activity.startActivity()
Fragment.startAcctivity()
ContextWrapper.startActivity()
Activity.startActivityForResult()
mInstrumentation.callActivityOnCreate(...)
ActivityManagerNative.onTransact()case START_ACTIVITY_TRANSACTION
