Added video capture capabilities retrieval and caching to VideoCaptureManager

content/browser/renderer_host/media/video_capture_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // VideoCaptureManager is used to open/close, start/stop, enumerate available
 // video capture devices, and manage VideoCaptureController's.
 // All functions are expected to be called from Browser::IO thread. Some helper
 // functions (*OnDeviceThread) will dispatch operations to the device thread.
 // VideoCaptureManager will open OS dependent instances of VideoCaptureDevice.
 // A device can only be opened once.
@@ skipping 64 matching lines @@
                              const DoneCB& done_cb);
 
   // Called by VideoCaptureHost to remove |client_handler|. If this is the last
   // client of the device, the |controller| and its VideoCaptureDevice may be
   // destroyed. The client must not access |controller| after calling this
   // function.
   void StopCaptureForClient(VideoCaptureController* controller,
                             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;
 
   // Check to see if |entry| has no clients left on its controller. If so,
   // remove it from the list of devices, and delete it asynchronously. |entry|
   // may be freed by this function.
   void DestroyDeviceEntryIfNoClients(DeviceEntry* entry);
 
   // Helpers to report an event to our Listener.
@@ skipping 75 matching lines @@
   // Set to true if using fake video capture devices for testing, false by
   // default. This is only used for the MEDIA_DEVICE_VIDEO_CAPTURE device type.
   bool use_fake_device_;
 
   // We cache the enumerated video capture devices in
   // GetAvailableDevicesOnDeviceThread() and then later look up the requested ID
   // when a device is created in DoStartDeviceOnDeviceThread(). Used only on the
   // 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);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_MANAGER_H_