work-in-progress patch to fix context lost black video

content/renderer/media/android/stream_texture_factory_impl.cc

 // Copyright 2014 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.
 
 #include "content/renderer/media/android/stream_texture_factory_impl.h"
 
 #include "cc/output/context_provider.h"
 #include "content/common/gpu/client/gpu_channel_host.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/renderer/gpu/stream_texture_host_android.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "ui/gfx/size.h"
 
 namespace content {
 
 namespace {
 
 class StreamTextureProxyImpl : public StreamTextureProxy,
                                public StreamTextureHost::Listener {
  public:
   explicit StreamTextureProxyImpl(StreamTextureHost* host);
   virtual ~StreamTextureProxyImpl();
 
   // StreamTextureProxy implementation:
-  virtual void BindToCurrentThread(int32 stream_id) OVERRIDE;
-  virtual void SetClient(cc::VideoFrameProvider::Client* client) OVERRIDE;
+  virtual void BindToLoop(int32 stream_id,
+                          cc::VideoFrameProvider::Client* client,
+                          scoped_refptr<base::MessageLoopProxy> loop) OVERRIDE;
   virtual void Release() OVERRIDE;
 
   // StreamTextureHost::Listener implementation:
   virtual void OnFrameAvailable() OVERRIDE;
   virtual void OnMatrixChanged(const float matrix[16]) OVERRIDE;
 
  private:
-  scoped_ptr<StreamTextureHost> host_;
+  void SetClient(cc::VideoFrameProvider::Client* client);
+  void BindOnThread(int32 stream_id,
+                    cc::VideoFrameProvider::Client* client,
+                    scoped_refptr<base::MessageLoopProxy> loop);
+
+  const scoped_ptr<StreamTextureHost> host_;
   scoped_refptr<base::MessageLoopProxy> loop_;
 
   base::Lock client_lock_;
   cc::VideoFrameProvider::Client* client_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(StreamTextureProxyImpl);
 };
 
 StreamTextureProxyImpl::StreamTextureProxyImpl(StreamTextureHost* host)
     : host_(host), client_(NULL) {}
 
 StreamTextureProxyImpl::~StreamTextureProxyImpl() {}
 
 void StreamTextureProxyImpl::Release() {
+  // Assumes this is the last reference to this object. So no need to acquire
+  // lock.
   SetClient(NULL);
-  if (loop_.get() && loop_.get() != base::MessageLoopProxy::current())
-    loop_->DeleteSoon(FROM_HERE, this);
-  else
+  if (!loop_.get() || loop_->BelongsToCurrentThread() ||
+      !loop_->DeleteSoon(FROM_HERE, this)) {
     delete this;
+  }
 }
 
 void StreamTextureProxyImpl::SetClient(cc::VideoFrameProvider::Client* client) {
   base::AutoLock lock(client_lock_);
   client_ = client;
 }
 
-void StreamTextureProxyImpl::BindToCurrentThread(int stream_id) {
-  loop_ = base::MessageLoopProxy::current();
+void StreamTextureProxyImpl::BindToLoop(
+    int32 stream_id,
+    cc::VideoFrameProvider::Client* client,
+    scoped_refptr<base::MessageLoopProxy> loop) {
+  if (loop->BelongsToCurrentThread()) {
+    BindOnThread(stream_id, client, loop);
+    return;
+  }
+  // Unretained is safe here only because the object is deleted on |loop_|
+  // thread.
+  loop->PostTask(FROM_HERE,
+                 base::Bind(&StreamTextureProxyImpl::BindOnThread,
+                            base::Unretained(this),
+                            stream_id,
+                            client,
+                            loop));
+}
+
+void StreamTextureProxyImpl::BindOnThread(
+    int32 stream_id,
+    cc::VideoFrameProvider::Client* client,
+    scoped_refptr<base::MessageLoopProxy> loop) {

[no sievers, 2014/09/15 19:00:39]

DCHECK(!client || (client && loop));
DCHECK(!loop_ || (loop == loop_));

[boliu, 2014/09/15 20:41:53]

Actually easier to just DCHECK(loop) in this case imo. Caller have to always
supply a loop.
Done

+  loop_ = loop;
+  SetClient(client);

[no sievers, 2014/09/15 19:00:40]

move this to BindToLoop()

[boliu, 2014/09/15 20:41:53]

Done.

   host_->BindToCurrentThread(stream_id, this);
 }
 
 void StreamTextureProxyImpl::OnFrameAvailable() {
   base::AutoLock lock(client_lock_);
   if (client_)
     client_->DidReceiveFrame();
 }
 
 void StreamTextureProxyImpl::OnMatrixChanged(const float matrix[16]) {
@@ skipping 54 matching lines @@
 
 void StreamTextureFactoryImpl::SetStreamTextureSize(int32 stream_id,
                                                     const gfx::Size& size) {
   channel_->Send(new GpuStreamTextureMsg_SetSize(stream_id, size));
 }
 
 gpu::gles2::GLES2Interface* StreamTextureFactoryImpl::ContextGL() {
   return context_provider_->ContextGL();
 }
 
+void StreamTextureFactoryImpl::AddObserver(
+    StreamTextureFactoryContextObserver* obs) {
+}
+
+void StreamTextureFactoryImpl::RemoveObserver(
+    StreamTextureFactoryContextObserver* obs) {
+}
+
 }  // namespace content