Fix lifecycle-vs-threads of GpuVDAContext3D.

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 5ffdda184c02ec26dee41f10d9817c7e46796466..75f6728319c74e3ce132bc2c190e782339fd2d50 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -21,6 +21,7 @@
 #include "content/common/gpu/gpu_process_launch_causes.h"
 #include "content/public/renderer/render_thread.h"
 #include "ipc/ipc_channel_proxy.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
 #include "ui/gfx/native_widget_types.h"
 
 class AppCacheDispatcher;
@@ -218,9 +219,12 @@ class CONTENT_EXPORT RenderThreadImpl : public content::RenderThread,
   // Returns a graphics context shared among all
   // RendererGpuVideoDecoderFactories, or NULL on error.  Context remains owned
   // by this class and must be null-tested before each use to detect context
-  // loss.  The returned WeakPtr<> is only valid on the compositor thread when
+  // loss.  The returned context is only valid on the compositor thread when
   // threaded compositing is enabled.
-  base::WeakPtr<WebGraphicsContext3DCommandBufferImpl> GetGpuVDAContext3D();
+  WebGraphicsContext3DCommandBufferImpl* GetGpuVDAContext3D();
+
+  // Handle loss of the shared GpuVDAContext3D context above.
+  static void OnGpuVDAContextLoss();
 
   // AudioRendererMixerManager instance which manages renderer side mixer
   // instances shared based on configured audio parameters.  Lazily created on
@@ -299,6 +303,15 @@ class CONTENT_EXPORT RenderThreadImpl : public content::RenderThread,
 
   ObserverList<content::RenderProcessObserver> observers_;
 
+  class GpuVDAContextLostCallback
+      : public WebKit::WebGraphicsContext3D::WebGraphicsContextLostCallback {

[piman, 2012/08/13 17:45:06]

Note: I'm fine with this, but FYI you can declare the inner class here and
define it in the .cc file, which does let you get rid of the header.

[Ami GONE FROM CHROMIUM, 2012/08/13 17:55:38]

Taking advantage of the scoped_ptr for auto-dtor goodness requires a full
declaration here, not just a fwd-declaration.

[piman, 2012/08/13 18:35:57]

Nah, you only need it with the destructor of RenderThreadImpl

+   public:
+    GpuVDAContextLostCallback();
+    virtual ~GpuVDAContextLostCallback();
+    virtual void onContextLost();
+  };
+
+  scoped_ptr<GpuVDAContextLostCallback> context_lost_cb_;
   scoped_ptr<WebGraphicsContext3DCommandBufferImpl> gpu_vda_context3d_;
 
   scoped_ptr<content::AudioRendererMixerManager> audio_renderer_mixer_manager_;