enable video capture to support sharing across multiple renderer processes

content/browser/renderer_host/media/video_capture_host.h

Index: content/browser/renderer_host/media/video_capture_host.h
===================================================================
--- content/browser/renderer_host/media/video_capture_host.h	(revision 105502)
+++ content/browser/renderer_host/media/video_capture_host.h	(working copy)
@@ -88,6 +88,12 @@
   // between a VideCaptureMessageFilter and a VideoCaptureHost.
   void OnStartCapture(int device_id,
                       const media::VideoCaptureParams& params);
+  void OnControllerAdded(
+      int device_id, const media::VideoCaptureParams& params,
+      VideoCaptureController* controller);
+  void DoControllerAddedOnIOThreead(
+      int device_id, const media::VideoCaptureParams params,
+      VideoCaptureController* controller);
 
   // IPC message: Stop capture on device referenced by |device_id|.
   void OnStopCapture(int device_id);
@@ -125,13 +131,20 @@
   // Handle error coming from VideoCaptureDevice.
   void DoHandleError(int device_id);
 
+  // Helpers.
+  media_stream::VideoCaptureManager* GetVideoCaptureManager();
+
   typedef std::map<VideoCaptureControllerID,
                    scoped_refptr<VideoCaptureController> >EntryMap;
-
   // A map of VideoCaptureControllerID to VideoCaptureController
   // objects that is currently active.
   EntryMap entries_;
 
+  typedef std::map<VideoCaptureControllerID,
+                   media::VideoCapture::State>EntryState;

[scherkus (not reviewing), 2011/10/19 18:02:21]

nit: space between > and EntryState

[wjia(left Chromium), 2011/10/21 00:56:13]

Done.

+  // Record state of each VideoCaptureControllerID.
+  EntryState entry_state_;

[perkj_chrome, 2011/10/17 08:39:43]

why two maps? Combine?

[wjia(left Chromium), 2011/10/21 00:56:13]

EntryState indicates that host has got StartCapture call. Since controller is
obtained via thread switching (from IO thread to manger's device thread, and
back to IO thread), host need to know the state based on which different action
is taken. An example is when StopCapture comes in before host obtains
controller.

+
   // Used to get a pointer to VideoCaptureManager to start/stop capture devices.
   const content::ResourceContext* resource_context_;