Fix lifecycle-vs-threads of GpuVDAContext3D.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 35ab4ecd08337a77dcb129615ca53d7817e2c77d..35ae77508bdea6148b4d8bee6f93bf8e5e1e1519 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -746,27 +746,41 @@ void RenderThreadImpl::PostponeIdleNotification() {
   idle_notifications_to_skip_ = 2;
 }
 
-base::WeakPtr<WebGraphicsContext3DCommandBufferImpl>
-RenderThreadImpl::GetGpuVDAContext3D() {
-  // If we already handed out a pointer to a context and it's been lost, create
-  // a new one.
-  if (gpu_vda_context3d_.get() && gpu_vda_context3d_->isContextLost()) {
-    if (compositor_thread()) {
-      compositor_thread()->GetWebThread()->message_loop()->DeleteSoon(
-          FROM_HERE, gpu_vda_context3d_.release());
-    } else {
-      gpu_vda_context3d_.reset();
-    }
+class GpuVDAContextLostCallback
+    : public WebKit::WebGraphicsContext3D::WebGraphicsContextLostCallback {
+ public:
+  virtual void onContextLost() {
+    ChildThread::current()->message_loop()->PostTask(FROM_HERE, base::Bind(
+        &RenderThreadImpl::OnGpuVDAContextLoss));
+  }
+};
+
+/* static */
+void RenderThreadImpl::OnGpuVDAContextLoss() {
+  RenderThreadImpl* self = RenderThreadImpl::current();
+  DCHECK(self);
+  if (!self->gpu_vda_context3d_.get())
+    return;
+  if (self->compositor_thread()) {
+    self->compositor_thread()->GetWebThread()->message_loop()->DeleteSoon(
+        FROM_HERE, self->gpu_vda_context3d_.release());
+  } else {
+    self->gpu_vda_context3d_.reset();
   }
+}
+
+WebGraphicsContext3DCommandBufferImpl*
+RenderThreadImpl::GetGpuVDAContext3D() {
+  static GpuVDAContextLostCallback* context_lost_cb =
+      new GpuVDAContextLostCallback();

[piman, 2012/08/13 17:23:35]

Why the need to leak it? Could it be a scoped_ptr field on RenderThreadImpl? The
compositor thread is shut down in the destructor, so it should be safe.

[Ami GONE FROM CHROMIUM, 2012/08/13 17:38:16]

Done, at the cost of having to 
#include
"third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
from render_thread_impl.h

   if (!gpu_vda_context3d_.get()) {
     gpu_vda_context3d_.reset(
         WebGraphicsContext3DCommandBufferImpl::CreateOffscreenContext(
             this, WebKit::WebGraphicsContext3D::Attributes(),
             GURL("chrome://gpu/RenderThreadImpl::GetGpuVDAContext3D")));
+    gpu_vda_context3d_->setContextLostCallback(context_lost_cb);
   }
-  if (!gpu_vda_context3d_.get())
-    return base::WeakPtr<WebGraphicsContext3DCommandBufferImpl>();
-  return gpu_vda_context3d_->AsWeakPtr();
+  return gpu_vda_context3d_.get();
 }
 
 content::AudioRendererMixerManager*