Bug 1103400 - add autofocus support to WebRTC on Gonk, r=aosmond,jesup

dom/media/webrtc/MediaEngineGonkVideoSource.cpp

@@ -329,6 +329,15 @@ MediaEngineGonkVideoSource::StartImpl(webrtc::CaptureCapability aCapability) {
   mCameraControl->Start(&config);
   mCameraControl->Set(CAMERA_PARAM_PICTURE_SIZE, config.mPreviewSize);
 
+  nsTArray<nsString> focusModes;
+  mCameraControl->Get(CAMERA_PARAM_SUPPORTED_FOCUSMODES, focusModes);
+  for (nsTArray<nsString>::index_type i = 0; i < focusModes.Length(); ++i) {
+    if (focusModes[i].EqualsASCII("continuous-video")) {
+      mCameraControl->Set(CAMERA_PARAM_FOCUSMODE, focusModes[i]);
+      break;
+    }
+  }
+
   hal::RegisterScreenConfigurationObserver(this);
 }