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);
+
+  const scoped_ptr<StreamTextureHost> host_;
+
+  base::Lock lock_;
   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() {
-  SetClient(NULL);
-  if (loop_.get() && loop_.get() != base::MessageLoopProxy::current())
-    loop_->DeleteSoon(FROM_HERE, this);
-  else
+  base::AutoLock lock(lock_);
+  client_ = NULL;
+  if (!loop_.get() || loop_.get() != base::MessageLoopProxy::current() ||

[qinmin, 2014/09/15 17:16:26]

so if loop_.get() != base::MessageLoopProxy::current(), we will call "delete
this" instead of loop_->DeleteSoon(FROM_HERE, this)? 

[boliu, 2014/09/15 17:54:07]

Done.

+      !loop_->DeleteSoon(FROM_HERE, this)) {
     delete this;
+  }
 }
 
-void StreamTextureProxyImpl::SetClient(cc::VideoFrameProvider::Client* client) {
-  base::AutoLock lock(client_lock_);
-  client_ = client;
+void StreamTextureProxyImpl::BindToLoop(
+    int32 stream_id,
+    cc::VideoFrameProvider::Client* client,
+    scoped_refptr<base::MessageLoopProxy> loop) {
+  base::AutoLock lock(lock_);
+  DCHECK(loop.get());
+  loop_ = loop;
+
+  if (loop.get() != base::MessageLoopProxy::current()) {

[qinmin, 2014/09/15 17:16:26]

It doesn't seem to me that we will ever enter this if statement/
Put a NOT_REACHED() here and we can remove that BindOnThread call.

[boliu, 2014/09/15 17:54:07]

Umm....webview will get here, but webview doesn't use this instance of proxy. I
think we should keep it..

+    // 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));
+  } else {
+    client_ = client;
+    host_->BindToCurrentThread(stream_id, this);
+  }
 }
 
-void StreamTextureProxyImpl::BindToCurrentThread(int stream_id) {
-  loop_ = base::MessageLoopProxy::current();
+void StreamTextureProxyImpl::BindOnThread(
+    int32 stream_id,
+    cc::VideoFrameProvider::Client* client) {
+  {
+    base::AutoLock lock(lock_);
+    client_ = client;
+  }
   host_->BindToCurrentThread(stream_id, this);
 }
 
 void StreamTextureProxyImpl::OnFrameAvailable() {
-  base::AutoLock lock(client_lock_);
+  base::AutoLock lock(lock_);
   if (client_)
     client_->DidReceiveFrame();
 }
 
 void StreamTextureProxyImpl::OnMatrixChanged(const float matrix[16]) {
-  base::AutoLock lock(client_lock_);
+  base::AutoLock lock(lock_);
   if (client_)
     client_->DidUpdateMatrix(matrix);
 }
 
 }  // namespace
 
 // static
 scoped_refptr<StreamTextureFactoryImpl> StreamTextureFactoryImpl::Create(
     const scoped_refptr<cc::ContextProvider>& context_provider,
     GpuChannelHost* channel,
@@ skipping 43 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