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 0688b4bab22375ec10bd5d49869307009a2043dd..3b74417cbf823c0e9d235953809fb40a2cadaaef 100644
--- a/media/video/capture/video_capture_device.cc
+++ b/media/video/capture/video_capture_device.cc
@@ -79,4 +79,10 @@ int VideoCaptureDevice::GetPowerLineFrequencyForLocation() const {
   return kPowerLine60Hz;
 }
 
+bool VideoCaptureDevice::InitializeImageCapture(
+    const ImageCaptureFormat& image_format,
+    scoped_ptr<ImageClient> client) {
+  return false;
+}
+
 }  // namespace media