Make VideoCaptureController single-threaded and not ref counted.

content/browser/renderer_host/media/video_capture_host.cc

Index: content/browser/renderer_host/media/video_capture_host.cc
diff --git a/content/browser/renderer_host/media/video_capture_host.cc b/content/browser/renderer_host/media/video_capture_host.cc
index 9d3c6344746433dce87b0abcb4e5da022cd4fd0f..f85925d2df56a23cf928314b38064bdb54e9f642 100644
--- a/content/browser/renderer_host/media/video_capture_host.cc
+++ b/content/browser/renderer_host/media/video_capture_host.cc
@@ -15,12 +15,7 @@
 namespace content {
 
 struct VideoCaptureHost::Entry {

[Ami GONE FROM CHROMIUM, 2013/09/13 21:17:59]

What's the point of this struct now? 
(feels like the answer is either "oops, no longer necessary" or "shhh!  I'm
doing something icky with managing weakptrs across threads!  Don't look too
closely!"; I'm hoping the answer is the former :))

[ncarter (slow), 2013/09/14 00:07:24]

What was the point of it before?

The point of this struct is to give you and me jobs. As to the point of that,
it's a harder question to answer.

Nuked it from space.

-  Entry(VideoCaptureController* controller)
-      : controller(controller) {}
-
-  ~Entry() {}
-
-  scoped_refptr<VideoCaptureController> controller;
+  base::WeakPtr<VideoCaptureController> controller;
 };
 
 VideoCaptureHost::VideoCaptureHost(MediaStreamManager* media_stream_manager)
@@ -222,7 +217,7 @@ void VideoCaptureHost::OnStartCapture(int device_id,
   VideoCaptureControllerID controller_id(device_id);
   DCHECK(entries_.find(controller_id) == entries_.end());
 
-  entries_[controller_id] = new Entry(NULL);
+  entries_[controller_id] = new Entry();
   media_stream_manager_->video_capture_manager()->StartCaptureForClient(
       params, PeerHandle(), controller_id, this, base::Bind(
           &VideoCaptureHost::OnControllerAdded, this, device_id, params));
@@ -230,28 +225,28 @@ void VideoCaptureHost::OnStartCapture(int device_id,
 
 void VideoCaptureHost::OnControllerAdded(
     int device_id, const media::VideoCaptureParams& params,
-    VideoCaptureController* controller) {
+    base::WeakPtr<VideoCaptureController> controller) {
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&VideoCaptureHost::DoControllerAddedOnIOThread,
-                 this, device_id, params, make_scoped_refptr(controller)));
+                 this, device_id, params, controller));
 }
 
 void VideoCaptureHost::DoControllerAddedOnIOThread(
     int device_id, const media::VideoCaptureParams params,
-    VideoCaptureController* controller) {
+    base::WeakPtr<VideoCaptureController> controller) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   VideoCaptureControllerID controller_id(device_id);
   EntryMap::iterator it = entries_.find(controller_id);
   if (it == entries_.end()) {
     if (controller) {
       media_stream_manager_->video_capture_manager()->StopCaptureForClient(
-          controller, controller_id, this);
+          controller.get(), controller_id, this);
     }
     return;
   }
 
-  if (controller == NULL) {
+  if (!controller) {
     Send(new VideoCaptureMsg_StateChanged(device_id,
                                           VIDEO_CAPTURE_STATE_ERROR));
     delete it->second;
@@ -286,8 +281,8 @@ void VideoCaptureHost::OnReceiveEmptyBuffer(int device_id, int buffer_id) {
   VideoCaptureControllerID controller_id(device_id);
   EntryMap::iterator it = entries_.find(controller_id);
   if (it != entries_.end()) {
-    scoped_refptr<VideoCaptureController> controller = it->second->controller;
-    if (controller.get())
+    base::WeakPtr<VideoCaptureController> controller = it->second->controller;
+    if (controller)
       controller->ReturnBuffer(controller_id, this, buffer_id);
   }
 }
@@ -300,10 +295,9 @@ void VideoCaptureHost::DeleteVideoCaptureControllerOnIOThread(
   if (it == entries_.end())
     return;
 
-  VideoCaptureController* controller = it->second->controller.get();
-  if (controller) {
+  if (it->second->controller) {
     media_stream_manager_->video_capture_manager()->StopCaptureForClient(
-        controller, controller_id, this);
+        it->second->controller.get(), controller_id, this);
   }
   delete it->second;
   entries_.erase(controller_id);