Removing singleton property of MediaStreamManager and creating thread first when needed.

content/browser/renderer_host/media/video_capture_host.h

Index: content/browser/renderer_host/media/video_capture_host.h
diff --git a/content/browser/renderer_host/media/video_capture_host.h b/content/browser/renderer_host/media/video_capture_host.h
index 335ee4b1a6538810fe5fc1f7760b6e75d2f9a97f..e0c086956554ab0fa0580f62d288ffd3fd164d67 100644
--- a/content/browser/renderer_host/media/video_capture_host.h
+++ b/content/browser/renderer_host/media/video_capture_host.h
@@ -43,11 +43,15 @@
 #include "content/browser/renderer_host/media/video_capture_controller.h"
 #include "ipc/ipc_message.h"
 
+namespace content {
+class ResourceContext;
+}  // namespace content
+
 class VideoCaptureHost
     : public BrowserMessageFilter,
       public VideoCaptureControllerEventHandler {
  public:
-  VideoCaptureHost();
+  VideoCaptureHost(const content::ResourceContext* resource_context);
 
   // BrowserMessageFilter implementation.
   virtual void OnChannelClosing();
@@ -127,6 +131,9 @@ class VideoCaptureHost
   // objects that is currently active.
   EntryMap entries_;
 
+  // Used to get a pointer to VideoCaptureManager to start/stop capture devices.
+  const content::ResourceContext* resource_context_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureHost);
 };