Screen Video Capture: Implement suspend optimization.

media/capture/content/android/screen_capture_machine_android.h

Index: media/capture/content/android/screen_capture_machine_android.h
diff --git a/media/capture/content/android/screen_capture_machine_android.h b/media/capture/content/android/screen_capture_machine_android.h
index 84bf1c71378d03049ee345776971907614eb8921..41ab2b66ed2459cc39af1dcc5bb85b71a9537196 100644
--- a/media/capture/content/android/screen_capture_machine_android.h
+++ b/media/capture/content/android/screen_capture_machine_android.h
@@ -55,6 +55,8 @@ class ScreenCaptureMachineAndroid : public media::VideoCaptureMachine {
   void Start(const scoped_refptr<media::ThreadSafeCaptureOracle>& oracle_proxy,
              const media::VideoCaptureParams& params,
              const base::Callback<void(bool)> callback) override;
+  void Suspend() override;
+  void Resume() override;

[braveyao, 2016/09/26 17:14:47]

No definition to these two functions? 

[miu, 2016/09/27 20:46:50]

Oh no! Sorry, I missed that. Please see most recent patch set.

   void Stop(const base::Closure& callback) override;
   void MaybeCaptureForRefresh() override;
 
@@ -68,6 +70,9 @@ class ScreenCaptureMachineAndroid : public media::VideoCaptureMachine {
   // Java VideoCaptureAndroid instance.
   base::android::ScopedJavaLocalRef<jobject> j_capture_;
 
+  // True while frame capture has been suspended.
+  bool suspend_frame_capture_;

[braveyao, 2016/09/26 17:14:46]

Due to above comments, this variable is not used at all.

[miu, 2016/09/27 20:46:50]

It is now. ;)

+
   DISALLOW_COPY_AND_ASSIGN(ScreenCaptureMachineAndroid);
 };