Add still image capture interface for VideoCaptureDevice.

media/video/capture/video_capture_device.cc

Index: media/video/capture/video_capture_device.cc
diff --git a/media/video/capture/video_capture_device.cc b/media/video/capture/video_capture_device.cc
index 3aa18269f013b22f7e008d7b00b85ee3cd5d74b6..675476b2b003b6406d009f1cae3832d9b852f661 100644
--- a/media/video/capture/video_capture_device.cc
+++ b/media/video/capture/video_capture_device.cc
@@ -76,4 +76,10 @@ int VideoCaptureDevice::GetPowerLineFrequencyForLocation() const {
   return kPowerLine60Hz;
 }
 
+void VideoCaptureDevice::InitializeImageCapture(
+    const ImageCaptureFormat& image_format,
+    scoped_ptr<ImageClient> client) {
+  client->OnError("Not supported");

[wuchengli, 2014/09/09 05:53:21]

The client can know if image capture is supported by
GetDeviceSupportedImageFormats. I think we can just have an empty implementation
like CloseImageCapture and CaptureImage. If you want to  call OnError, the other
two functions should call OnError, too.

[Owen Lin, 2014/09/11 06:17:59]

Good point.

+}
+
 }  // namespace media