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

content/browser/android/in_process/synchronous_compositor_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/browser/android/in_process/synchronous_compositor_factory_impl.h"
 
+#include "base/observer_list.h"
 #include "content/browser/android/in_process/synchronous_compositor_output_surface.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/renderer/gpu/frame_swap_message_queue.h"
 #include "gpu/command_buffer/client/gl_in_process_context.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "ui/gl/android/surface_texture.h"
 #include "ui/gl/gl_surface.h"
 #include "ui/gl/gl_surface_stub.h"
 #include "webkit/common/gpu/context_provider_in_process.h"
 #include "webkit/common/gpu/webgraphicscontext3d_in_process_command_buffer_impl.h"
@@ skipping 80 matching lines @@
     scoped_ptr<gpu::GLInProcessContext> context,
     const blink::WebGraphicsContext3D::Attributes& attributes) {
   if (!context.get())
     return scoped_ptr<WebGraphicsContext3DInProcessCommandBufferImpl>();
 
   return scoped_ptr<WebGraphicsContext3DInProcessCommandBufferImpl>(
       WebGraphicsContext3DInProcessCommandBufferImpl::WrapContext(
           context.Pass(), attributes));
 }
 
-class VideoContextProvider
+}  // namespace
+
+class SynchronousCompositorFactoryImpl::VideoContextProvider
     : public StreamTextureFactorySynchronousImpl::ContextProvider {
  public:
   VideoContextProvider(
       scoped_ptr<gpu::GLInProcessContext> gl_in_process_context)
       : gl_in_process_context_(gl_in_process_context.get()) {
 
     context_provider_ = webkit::gpu::ContextProviderInProcess::Create(
         WrapContext(gl_in_process_context.Pass()),
         "Video-Offscreen-main-thread");
     context_provider_->BindToCurrentThread();
   }
 
   virtual scoped_refptr<gfx::SurfaceTexture> GetSurfaceTexture(
       uint32 stream_id) OVERRIDE {
     return gl_in_process_context_->GetSurfaceTexture(stream_id);
   }
 
   virtual gpu::gles2::GLES2Interface* ContextGL() OVERRIDE {
     return context_provider_->ContextGL();
   }
 
+  virtual void AddObserver(StreamTextureFactoryContextObserver* obs) OVERRIDE {
+    observer_list_.AddObserver(obs);
+  }
+
+  virtual void RemoveObserver(
+      StreamTextureFactoryContextObserver* obs) OVERRIDE {
+    observer_list_.RemoveObserver(obs);
+  }
+
+  void LoseContext() {
+    FOR_EACH_OBSERVER(
+        StreamTextureFactoryContextObserver, observer_list_, OnContextLost());
+  }
+
+  void RestoreContext() {
+    FOR_EACH_OBSERVER(StreamTextureFactoryContextObserver,
+                      observer_list_,
+                      OnContextRestored());
+  }
+
  private:
   friend class base::RefCountedThreadSafe<VideoContextProvider>;
   virtual ~VideoContextProvider() {}
 
   scoped_refptr<cc::ContextProvider> context_provider_;
   gpu::GLInProcessContext* gl_in_process_context_;
+  ObserverList<StreamTextureFactoryContextObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoContextProvider);
 };
 
-}  // namespace
-
 using webkit::gpu::WebGraphicsContext3DInProcessCommandBufferImpl;
 
 SynchronousCompositorFactoryImpl::SynchronousCompositorFactoryImpl()
     : record_full_layer_(true),
       num_hardware_compositors_(0) {
   SynchronousCompositorFactory::SetInstance(this);
 }
 
 SynchronousCompositorFactoryImpl::~SynchronousCompositorFactoryImpl() {}
 
@@ skipping 68 matching lines @@
 webkit::gpu::WebGraphicsContext3DImpl*
 SynchronousCompositorFactoryImpl::CreateOffscreenGraphicsContext3D(
     const blink::WebGraphicsContext3D::Attributes& attributes) {
   return WrapContextWithAttributes(CreateOffscreenContext(attributes),
                                    attributes).release();
 }
 
 void SynchronousCompositorFactoryImpl::CompositorInitializedHardwareDraw() {
   base::AutoLock lock(num_hardware_compositor_lock_);
   num_hardware_compositors_++;
+  if (num_hardware_compositors_ == 1 && main_thread_proxy_) {
+    main_thread_proxy_->PostTask(
+        FROM_HERE,
+        base::Bind(
+            &SynchronousCompositorFactoryImpl::RestoreContextOnMainThread,
+            base::Unretained(this)));
+  }
 }
 
 void SynchronousCompositorFactoryImpl::CompositorReleasedHardwareDraw() {
   base::AutoLock lock(num_hardware_compositor_lock_);
   DCHECK_GT(num_hardware_compositors_, 0u);
   num_hardware_compositors_--;
+  if (!num_hardware_compositors_ && main_thread_proxy_) {
+    main_thread_proxy_->PostTask(
+        FROM_HERE,
+        base::Bind(&SynchronousCompositorFactoryImpl::LoseContextOnMainThread,
+                   base::Unretained(this)));
+  }
+}
+
+void SynchronousCompositorFactoryImpl::LoseContextOnMainThread() {
+  if (video_context_provider_)
+    video_context_provider_->LoseContext();
+}
+
+void SynchronousCompositorFactoryImpl::RestoreContextOnMainThread() {
+  if (video_context_provider_)
+    video_context_provider_->RestoreContext();
 }
 
 bool SynchronousCompositorFactoryImpl::CanCreateMainThreadContext() {
   base::AutoLock lock(num_hardware_compositor_lock_);
   return num_hardware_compositors_ > 0;
 }
 
 scoped_refptr<StreamTextureFactorySynchronousImpl::ContextProvider>
 SynchronousCompositorFactoryImpl::TryCreateStreamTextureFactory() {
+  {
+    base::AutoLock lock(num_hardware_compositor_lock_);
+    main_thread_proxy_ = base::MessageLoopProxy::current();
+  }
+
   // Always fail creation even if |video_context_provider_| is not NULL.
   // This is to avoid synchronous calls that may deadlock. Setting
   // |video_context_provider_| to null is also not safe since it makes
   // synchronous destruction uncontrolled and possibly deadlock.
   if (!CanCreateMainThreadContext()) {
     return
         scoped_refptr<StreamTextureFactorySynchronousImpl::ContextProvider>();
   }
 
   if (!video_context_provider_) {
@@ skipping 13 matching lines @@
   DCHECK(!service_);
   service_ = service;
 }
 
 void SynchronousCompositorFactoryImpl::SetRecordFullDocument(
     bool record_full_document) {
   record_full_layer_ = record_full_document;
 }
 
 }  // namespace content