Added video capture capabilities retrieval and caching to VideoCaptureManager

content/browser/renderer_host/media/video_capture_manager.h

Index: content/browser/renderer_host/media/video_capture_manager.h
diff --git a/content/browser/renderer_host/media/video_capture_manager.h b/content/browser/renderer_host/media/video_capture_manager.h
index 6f0b0ec4702dedd2e9e2f43caecee942542ec5e8..e13db133343081b1a89b9a763097414628be4a87 100644
--- a/content/browser/renderer_host/media/video_capture_manager.h
+++ b/content/browser/renderer_host/media/video_capture_manager.h
@@ -82,6 +82,12 @@ class CONTENT_EXPORT VideoCaptureManager : public MediaStreamProvider {
                             VideoCaptureControllerID client_id,
                             VideoCaptureControllerEventHandler* client_handler);
 
+  // Retrieve the available capture capabilities for a particular device. The
+  // capabilities are cached during GetAvailableDevicesOnDeviceThread() and
+  // updated on DoStartDeviceOnDeviceThread(). The call is synchronous.
+  const media::VideoCaptureCapabilities* EnumerateDeviceCapabilities(
+      const StreamDeviceInfo& device_info);
+
  private:
   virtual ~VideoCaptureManager();
   struct DeviceEntry;
@@ -177,6 +183,13 @@ class CONTENT_EXPORT VideoCaptureManager : public MediaStreamProvider {
   // device thread.
   media::VideoCaptureDevice::Names video_capture_devices_;
 
+  // Local cache of video capture capabilities, indexed by unique id. It is
+  // created in GetAvailableDevicesOnDeviceThread(), updated in
+  // DoStartDeviceOnDeviceThread() and retrieved for a particular device id in
+  // EnumerateDeviceCapabilities(), read only.
+  std::map<std::string, media::VideoCaptureCapabilities>
+      video_capture_capabilities_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureManager);
 };