Undo mistaken revert.

content/renderer/media/video_capture_impl_manager.h

Index: content/renderer/media/video_capture_impl_manager.h
diff --git a/content/renderer/media/video_capture_impl_manager.h b/content/renderer/media/video_capture_impl_manager.h
new file mode 100644
index 0000000000000000000000000000000000000000..f6f46d053c94df359a983b04bc13abf7d12a9ce6
--- /dev/null
+++ b/content/renderer/media/video_capture_impl_manager.h
@@ -0,0 +1,68 @@
+// Copyright (c) 2011 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.
+
+// VideoCaptureImplManager manages video capture devices in renderer process.
+// The video capture clients use AddDevice() to get a pointer to
+// video capture device. VideoCaputreImplManager supports multiple clients
+// accessing same device.
+
+#ifndef CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_MANAGER_H_
+#define CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_MANAGER_H_
+
+#include <list>
+#include <map>
+
+#include "base/message_loop_proxy.h"
+#include "base/synchronization/lock.h"
+#include "content/renderer/media/video_capture_impl.h"
+#include "content/renderer/video_capture_message_filter.h"
+#include "media/base/callback.h"
+#include "media/base/message_loop_factory.h"
+#include "media/video/capture/video_capture.h"
+
+class VideoCaptureImplManager {
+ public:
+  VideoCaptureImplManager();
+  ~VideoCaptureImplManager();
+
+  // Called by video capture client |handler| to add device referenced
+  // by |id| to VideoCaptureImplManager's list of opened device list.
+  // A pointer to VideoCapture is returned to client so that client can
+  // operate on that pointer, such as StartCaptrue, StopCapture.
+  static media::VideoCapture* AddDevice(
+      media::VideoCaptureSessionId id,
+      media::VideoCapture::EventHandler* handler);
+
+  // Called by video capture client |handler| to remove device referenced
+  // by |id| from VideoCaptureImplManager's list of opened device list.
+  static void RemoveDevice(media::VideoCaptureSessionId id,
+                           media::VideoCapture::EventHandler* handler);
+
+  static VideoCaptureImplManager* GetInstance();
+
+ private:
+  struct Device {
+    Device();
+    Device(VideoCaptureImpl* device,
+           media::VideoCapture::EventHandler* handler);
+    ~Device();
+
+    VideoCaptureImpl* vc;
+    std::list<media::VideoCapture::EventHandler*> clients;
+  };
+
+  void FreeDevice(VideoCaptureImpl* vc);
+
+  typedef std::map<media::VideoCaptureSessionId, Device> Devices;
+  Devices devices_;
+  base::Lock lock_;
+  scoped_refptr<base::MessageLoopProxy> ml_proxy_;
+  scoped_ptr<media::MessageLoopFactory> ml_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(VideoCaptureImplManager);
+};
+
+DISABLE_RUNNABLE_METHOD_REFCOUNT(VideoCaptureImplManager);
+
+#endif  // CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_MANAGER_H_