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

content/renderer/media/android/stream_texture_factory_impl.cc

Index: content/renderer/media/android/stream_texture_factory_impl.cc
diff --git a/content/renderer/media/android/stream_texture_factory_impl.cc b/content/renderer/media/android/stream_texture_factory_impl.cc
index da9a70f4ba732222b0af8b9adad6228310af8d78..6190d940a85c1643466b5b283b630e8d70e6e83b 100644
--- a/content/renderer/media/android/stream_texture_factory_impl.cc
+++ b/content/renderer/media/android/stream_texture_factory_impl.cc
@@ -22,8 +22,9 @@ class StreamTextureProxyImpl : public StreamTextureProxy,
   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:
@@ -31,7 +32,12 @@ class StreamTextureProxyImpl : public StreamTextureProxy,
   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_;
@@ -46,11 +52,13 @@ StreamTextureProxyImpl::StreamTextureProxyImpl(StreamTextureHost* host)
 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) {
@@ -58,8 +66,30 @@ void StreamTextureProxyImpl::SetClient(cc::VideoFrameProvider::Client* client) {
   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);
 }
 
@@ -134,4 +164,12 @@ gpu::gles2::GLES2Interface* StreamTextureFactoryImpl::ContextGL() {
   return context_provider_->ContextGL();
 }
 
+void StreamTextureFactoryImpl::AddObserver(
+    StreamTextureFactoryContextObserver* obs) {
+}
+
+void StreamTextureFactoryImpl::RemoveObserver(
+    StreamTextureFactoryContextObserver* obs) {
+}
+
 }  // namespace content