Video Capture: Allow suspension of individual devices.

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
index 1b7c28b3fb7218017e03aa6b80eb3e57c062f4cc..005e70dd3e253aa0a58f5668c4c3a4509c8fa5c0 100644
--- a/content/renderer/media/video_capture_impl_manager.h
+++ b/content/renderer/media/video_capture_impl_manager.h
@@ -5,8 +5,8 @@
 #ifndef CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_MANAGER_H_
 #define CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_MANAGER_H_
 
-#include <map>
 #include <memory>
+#include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
@@ -77,6 +77,10 @@ class CONTENT_EXPORT VideoCaptureImplManager {
   // picture loss or quality issues).
   void RequestRefreshFrame(media::VideoCaptureSessionId id);
 
+  // Requests frame delivery be suspended/resumed for a given capture session.
+  void Suspend(media::VideoCaptureSessionId id);
+  void Resume(media::VideoCaptureSessionId id);
+
   // Get supported formats supported by the device for the given session
   // ID. |callback| will be called on the IO thread.
   void GetDeviceSupportedFormats(media::VideoCaptureSessionId id,
@@ -88,7 +92,9 @@ class CONTENT_EXPORT VideoCaptureImplManager {
                              const VideoCaptureDeviceFormatsCB& callback);
 
   // Make all existing VideoCaptureImpl instances stop/resume delivering
-  // video frames to their clients, depends on flag |suspend|.
+  // video frames to their clients, depends on flag |suspend|. This is called in
+  // response to a RenderView-wide PageHidden/Shown() event. To suspend/resume
+  // an individual session, please call Suspend(id) or Resume(id).
   void SuspendDevices(bool suspend);
 
   VideoCaptureMessageFilter* video_capture_message_filter() const {
@@ -96,21 +102,19 @@ class CONTENT_EXPORT VideoCaptureImplManager {
   }
 
  protected:
-  virtual VideoCaptureImpl* CreateVideoCaptureImplForTesting(
+  virtual std::unique_ptr<VideoCaptureImpl> CreateVideoCaptureImplForTesting(
       media::VideoCaptureSessionId id,
       VideoCaptureMessageFilter* filter) const;
 
  private:
+  // Holds bookkeeping info for each VideoCaptureImpl shared by clients.
+  struct DeviceEntry;
+
   void StopCapture(int client_id, media::VideoCaptureSessionId id);
   void UnrefDevice(media::VideoCaptureSessionId id);
 
-  // The int is used to count clients of the corresponding VideoCaptureImpl.
-  // VideoCaptureImpl objects are owned by this object. But they are
-  // destroyed on the IO thread. These are raw pointers because we destroy
-  // them manually.
-  typedef std::map<media::VideoCaptureSessionId,
-                   std::pair<int, VideoCaptureImpl*>> VideoCaptureDeviceMap;
-  VideoCaptureDeviceMap devices_;
+  // Devices currently in use.
+  std::vector<DeviceEntry> devices_;
 
   // This is an internal ID for identifying clients of VideoCaptureImpl.
   // The ID is global for the render process.
@@ -122,6 +126,11 @@ class CONTENT_EXPORT VideoCaptureImplManager {
   // right thread.
   const scoped_refptr<base::SingleThreadTaskRunner> render_main_task_runner_;
 
+  // Set to true if SuspendDevices(true) was called. This, along with
+  // DeviceEntry::is_individually_suspended, is used to determine whether to
+  // take action when suspending/resuming each device.
+  bool is_suspending_all_;
+
   // Bound to the render thread.
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<VideoCaptureImplManager> weak_factory_;