getUserMeida: report device starting states

media/capture/video/android/java/src/org/chromium/media/VideoCaptureCamera2.java

Index: media/capture/video/android/java/src/org/chromium/media/VideoCaptureCamera2.java
diff --git a/media/capture/video/android/java/src/org/chromium/media/VideoCaptureCamera2.java b/media/capture/video/android/java/src/org/chromium/media/VideoCaptureCamera2.java
index 3997af9fbb2899fdb3ba39937f0d68f7c94950f0..1cecd90014f1edc68565fb85338231849659d912 100644
--- a/media/capture/video/android/java/src/org/chromium/media/VideoCaptureCamera2.java
+++ b/media/capture/video/android/java/src/org/chromium/media/VideoCaptureCamera2.java
@@ -97,6 +97,7 @@ public class VideoCaptureCamera2 extends VideoCapture {
                 return;
             }
             // Now wait for trigger on CrImageReaderListener.onImageAvailable();
+            nativeOnStarted(mNativeVideoCaptureDeviceAndroid);
             changeCameraStateAndNotify(CameraState.STARTED);
         }
 
@@ -114,6 +115,13 @@ public class VideoCaptureCamera2 extends VideoCapture {
     private class CrImageReaderListener implements ImageReader.OnImageAvailableListener {
         @Override
         public void onImageAvailable(ImageReader reader) {
+            synchronized (mCameraStateLock) {
+                if (mCameraState != CameraState.STARTED) {
+                    Log.e(TAG, "Get captured frame in unexpected state.");

[chfremer, 2017/02/16 01:00:50]

Is this really unexpected? 
If the camera can deliver frames before the state has changed to STARTED in
method onConfigured(), wouldn't hitting this code path and discarding the frame
be expected behavior?

[braveyao, 2017/02/17 20:37:21]

This check also includes the situation that getting captured frame after we stop
capture. Even I didn't encounter such situation with camera capture, but it does
happen to screen capture and caused some issues. So I define it as Error. Remove
the log here though.

+                    return;
+                }
+            }
+
             try (Image image = reader.acquireLatestImage()) {
                 if (image == null) return;