8504 Android Embedding PR27: Fix SurfaceView flicker in Fragment transactions (cla: yes)

8511 switch to newer APIs for shaders and filters (cla: yes)

8515 Add windows host_debug_unopt build test (cla: yes)

8517 Rename the blink namespace to flutter. (cla: yes)

8518 Remove the unused EnableBlink flag. (cla: yes)

8520 Rename the shell namespace to flutter. (cla: yes)

8523 Remove redundant specification of the

flutter

namespace in the engine. (cla: yes)

8524 Change Rect internal representation from Float32List to Float64List (cla: yes)

8525 Merge flutter/synchronization contents into fml. (cla: yes)