Revert 241425 "Aura: Don't create GL context for CreateSharedSur..."

Speculative revert for browser_tests failure on Linux Aura Tests
http://build.chromium.org/p/chromium.linux/builders/Linux%20Aura%20Tests/builds/207

> Aura: Don't create GL context for CreateSharedSurfaceHandle()
> 
> The context is used for blocking renders that are trying to create
>  a context after the GPU process crashed through comparing
>  gpu process IDs.
> 
> Remove this code as we can handle SwapCompositorFrame
>  more gracefully nowadays after resources were lost.
>  But still fail renderer view context creation when
>  gpu browser compositing gets turned off.
> 
> BUG=270179
> 
> Review URL: https://codereview.chromium.org/111063003

TBR=sievers@chromium.org

Review URL: https://codereview.chromium.org/118003002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241508 0039d316-1c4b-4281-b951-d872f2087c98

24 files changed, 131 insertions, 22 deletions

diff --git a/content/browser/aura/gpu_process_transport_factory.cc b/content/browser/aura/gpu_process_transport_factory.cc
index 7288155..ee92513 100644
--- a/content/browser/aura/gpu_process_transport_factory.cc
+++ b/content/browser/aura/gpu_process_transport_factory.cc
@@ -283,14 +283,24 @@ ui::ContextFactory* GpuProcessTransportFactory::AsContextFactory() {
   return this;
 }
 
-gfx::GLSurfaceHandle GpuProcessTransportFactory::GetSharedSurfaceHandle() {
+gfx::GLSurfaceHandle GpuProcessTransportFactory::CreateSharedSurfaceHandle() {
+  scoped_refptr<cc::ContextProvider> provider =
+      SharedMainThreadContextProvider();
+  if (!provider.get())
+    return gfx::GLSurfaceHandle();
+  typedef WebGraphicsContext3DCommandBufferImpl WGC3DCBI;
+  WGC3DCBI* context = static_cast<WGC3DCBI*>(provider->Context3d());
   gfx::GLSurfaceHandle handle = gfx::GLSurfaceHandle(
       gfx::kNullPluginWindow, gfx::TEXTURE_TRANSPORT);
+  handle.parent_gpu_process_id = context->GetGPUProcessID();
   handle.parent_client_id =
       BrowserGpuChannelHostFactory::instance()->GetGpuChannelId();
   return handle;
 }
 
+void GpuProcessTransportFactory::DestroySharedSurfaceHandle(
+    gfx::GLSurfaceHandle surface) {}
+
 scoped_refptr<ui::Texture> GpuProcessTransportFactory::CreateTransportClient(
     float device_scale_factor) {
   scoped_refptr<cc::ContextProvider> provider =
diff --git a/content/browser/aura/gpu_process_transport_factory.h b/content/browser/aura/gpu_process_transport_factory.h
index da977b5..13da92b 100644
--- a/content/browser/aura/gpu_process_transport_factory.h
+++ b/content/browser/aura/gpu_process_transport_factory.h
@@ -51,7 +51,9 @@ class GpuProcessTransportFactory
 
   // ImageTransportFactory implementation.
   virtual ui::ContextFactory* AsContextFactory() OVERRIDE;
-  virtual gfx::GLSurfaceHandle GetSharedSurfaceHandle() OVERRIDE;
+  virtual gfx::GLSurfaceHandle CreateSharedSurfaceHandle() OVERRIDE;
+  virtual void DestroySharedSurfaceHandle(
+      gfx::GLSurfaceHandle surface) OVERRIDE;
   virtual scoped_refptr<ui::Texture> CreateTransportClient(
       float device_scale_factor) OVERRIDE;
   virtual scoped_refptr<ui::Texture> CreateOwnedTexture(
diff --git a/content/browser/aura/image_transport_factory.h b/content/browser/aura/image_transport_factory.h
index 51bce67..fecb442 100644
--- a/content/browser/aura/image_transport_factory.h
+++ b/content/browser/aura/image_transport_factory.h
@@ -67,7 +67,13 @@ class CONTENT_EXPORT ImageTransportFactory {
   // Gets the image transport factory as a context factory for the compositor.
   virtual ui::ContextFactory* AsContextFactory() = 0;
 
-  virtual gfx::GLSurfaceHandle GetSharedSurfaceHandle() = 0;
+  // Creates a shared surface handle.
+  // Note: the handle may get lost at any time, a state that an
+  // ImageTransportFactoryObserver gets notified of.
+  virtual gfx::GLSurfaceHandle CreateSharedSurfaceHandle() = 0;
+
+  // Destroys a shared surface handle.
+  virtual void DestroySharedSurfaceHandle(gfx::GLSurfaceHandle surface) = 0;
 
   // Creates a transport texture for a given scale factor.
   virtual scoped_refptr<ui::Texture> CreateTransportClient(
diff --git a/content/browser/aura/no_transport_image_transport_factory.cc b/content/browser/aura/no_transport_image_transport_factory.cc
index d723e59..7f68e02 100644
--- a/content/browser/aura/no_transport_image_transport_factory.cc
+++ b/content/browser/aura/no_transport_image_transport_factory.cc
@@ -51,10 +51,13 @@ ui::ContextFactory* NoTransportImageTransportFactory::AsContextFactory() {
 }
 
 gfx::GLSurfaceHandle
-NoTransportImageTransportFactory::GetSharedSurfaceHandle() {
+NoTransportImageTransportFactory::CreateSharedSurfaceHandle() {
   return gfx::GLSurfaceHandle();
 }
 
+void NoTransportImageTransportFactory::DestroySharedSurfaceHandle(
+    gfx::GLSurfaceHandle surface) {}
+
 scoped_refptr<ui::Texture>
 NoTransportImageTransportFactory::CreateTransportClient(
     float device_scale_factor) {
diff --git a/content/browser/aura/no_transport_image_transport_factory.h b/content/browser/aura/no_transport_image_transport_factory.h
index e9fa650..dd551d9 100644
--- a/content/browser/aura/no_transport_image_transport_factory.h
+++ b/content/browser/aura/no_transport_image_transport_factory.h
@@ -23,7 +23,9 @@ class NoTransportImageTransportFactory : public ImageTransportFactory {
 
   // ImageTransportFactory implementation.
   virtual ui::ContextFactory* AsContextFactory() OVERRIDE;
-  virtual gfx::GLSurfaceHandle GetSharedSurfaceHandle() OVERRIDE;
+  virtual gfx::GLSurfaceHandle CreateSharedSurfaceHandle() OVERRIDE;
+  virtual void DestroySharedSurfaceHandle(gfx::GLSurfaceHandle surface)
+      OVERRIDE;
   virtual scoped_refptr<ui::Texture> CreateTransportClient(
       float device_scale_factor) OVERRIDE;
   virtual scoped_refptr<ui::Texture> CreateOwnedTexture(
diff --git a/content/browser/gpu/browser_gpu_channel_host_factory.cc b/content/browser/gpu/browser_gpu_channel_host_factory.cc
index 5faf7ba..d0ce8b4 100644
--- a/content/browser/gpu/browser_gpu_channel_host_factory.cc
+++ b/content/browser/gpu/browser_gpu_channel_host_factory.cc
@@ -359,6 +359,7 @@ void BrowserGpuChannelHostFactory::GpuChannelEstablished() {
 
   GetContentClient()->SetGpuInfo(pending_request_->gpu_info());
   gpu_channel_ = GpuChannelHost::Create(this,
+                                        pending_request_->gpu_host_id(),
                                         pending_request_->gpu_info(),
                                         pending_request_->channel_handle());
   gpu_host_id_ = pending_request_->gpu_host_id();
diff --git a/content/browser/renderer_host/gpu_message_filter.cc b/content/browser/renderer_host/gpu_message_filter.cc
index 4dc49bb..9068a40 100644
--- a/content/browser/renderer_host/gpu_message_filter.cc
+++ b/content/browser/renderer_host/gpu_message_filter.cc
@@ -11,7 +11,6 @@
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
-#include "content/browser/gpu/gpu_data_manager_impl_private.h"
 #include "content/browser/gpu/gpu_process_host.h"
 #include "content/browser/gpu/gpu_surface_tracker.h"
 #include "content/browser/renderer_host/render_widget_helper.h"
@@ -95,6 +94,24 @@ bool GpuMessageFilter::OnMessageReceived(
   return handled;
 }
 
+void GpuMessageFilter::SurfaceUpdated(int32 surface_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  typedef std::vector<linked_ptr<CreateViewCommandBufferRequest> > RequestList;
+  RequestList retry_requests;
+  retry_requests.swap(pending_requests_);
+  for (RequestList::iterator it = retry_requests.begin();
+      it != retry_requests.end(); ++it) {
+    if ((*it)->surface_id != surface_id) {
+      pending_requests_.push_back(*it);
+    } else {
+      linked_ptr<CreateViewCommandBufferRequest> request = *it;
+      OnCreateViewCommandBuffer(request->surface_id,
+                                request->init_params,
+                                request->reply.release());
+    }
+  }
+}
+
 void GpuMessageFilter::BeginFrameSubscription(
     int route_id,
     scoped_ptr<RenderWidgetHostViewFrameSubscriber> subscriber) {
@@ -175,10 +192,16 @@ void GpuMessageFilter::OnCreateViewCommandBuffer(
                 << " tried to access a surface for renderer " << renderer_id;
   }
 
-  if (compositing_surface.parent_client_id &&
-      !GpuDataManagerImpl::GetInstance()->CanUseGpuBrowserCompositor()) {
-    // For the renderer to fall back to software also.
-    compositing_surface = gfx::GLSurfaceHandle();
+  if (compositing_surface.parent_gpu_process_id &&
+      compositing_surface.parent_gpu_process_id != gpu_process_id_) {
+    // If the current handle for the surface is using a different (older) gpu
+    // host, it means the GPU process died and we need to wait until the UI
+    // re-allocates the surface in the new process.
+    linked_ptr<CreateViewCommandBufferRequest> request(
+        new CreateViewCommandBufferRequest(
+            surface_id, init_params, reply.Pass()));
+    pending_requests_.push_back(request);
+    return;
   }
 
   GpuProcessHost* host = GpuProcessHost::FromID(gpu_process_id_);
diff --git a/content/browser/renderer_host/gpu_message_filter.h b/content/browser/renderer_host/gpu_message_filter.h
index d43b62e..5492ad9 100644
--- a/content/browser/renderer_host/gpu_message_filter.h
+++ b/content/browser/renderer_host/gpu_message_filter.h
@@ -39,6 +39,10 @@ class GpuMessageFilter : public BrowserMessageFilter {
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  bool* message_was_ok) OVERRIDE;
 
+  // Signals that the handle for a surface id was updated, and it may be time to
+  // unblock existing CreateViewCommandBuffer requests using that surface.
+  void SurfaceUpdated(int32 surface_id);
+
   // This set of API is used to subscribe to frame presentation events.
   // See RenderWidgetHostViewFrameSubscriber for more details.
   void BeginFrameSubscription(
@@ -80,6 +84,7 @@ class GpuMessageFilter : public BrowserMessageFilter {
   bool share_contexts_;
 
   scoped_refptr<RenderWidgetHelper> render_widget_helper_;
+  std::vector<linked_ptr<CreateViewCommandBufferRequest> > pending_requests_;
 
   base::WeakPtrFactory<GpuMessageFilter> weak_ptr_factory_;
 
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index e13ef7d..17444b3 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -1493,6 +1493,15 @@ base::TimeDelta RenderProcessHostImpl::GetChildProcessIdleTime() const {
   return base::TimeTicks::Now() - child_process_activity_time_;
 }
 
+void RenderProcessHostImpl::SurfaceUpdated(int32 surface_id) {
+  if (!gpu_message_filter_)
+    return;
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
+      &GpuMessageFilter::SurfaceUpdated,
+      gpu_message_filter_,
+      surface_id));
+}
+
 void RenderProcessHostImpl::ResumeRequestsForView(int route_id) {
   widget_helper_->ResumeRequestsForView(route_id);
 }
diff --git a/content/browser/renderer_host/render_process_host_impl.h b/content/browser/renderer_host/render_process_host_impl.h
index 46418dd..d69e568 100644
--- a/content/browser/renderer_host/render_process_host_impl.h
+++ b/content/browser/renderer_host/render_process_host_impl.h
@@ -119,6 +119,7 @@ class CONTENT_EXPORT RenderProcessHostImpl
   virtual bool FastShutdownForPageCount(size_t count) OVERRIDE;
   virtual bool FastShutdownStarted() const OVERRIDE;
   virtual base::TimeDelta GetChildProcessIdleTime() const OVERRIDE;
+  virtual void SurfaceUpdated(int32 surface_id) OVERRIDE;
   virtual void ResumeRequestsForView(int route_id) OVERRIDE;
 #if defined(ENABLE_WEBRTC)
   virtual void EnableAecDump(const base::FilePath& file) OVERRIDE;
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 586785a..9f064f2 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -359,6 +359,12 @@ gfx::GLSurfaceHandle RenderWidgetHostImpl::GetCompositingSurface() {
   return gfx::GLSurfaceHandle();
 }
 
+void RenderWidgetHostImpl::CompositingSurfaceUpdated() {
+  GpuSurfaceTracker::Get()->SetSurfaceHandle(
+      surface_id_, GetCompositingSurface());
+  process_->SurfaceUpdated(surface_id_);
+}
+
 void RenderWidgetHostImpl::ResetSizeAndRepaintPendingFlags() {
   resize_ack_pending_ = false;
   if (repaint_ack_pending_) {
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index d056a2f..22dbdbe 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -493,6 +493,10 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   void ParentChanged(gfx::NativeViewId new_parent);
 #endif
 
+  // Signals that the compositing surface was updated, e.g. after a lost context
+  // event.
+  void CompositingSurfaceUpdated();
+
   void set_allow_privileged_mouse_lock(bool allow) {
     allow_privileged_mouse_lock_ = allow;
   }
diff --git a/content/browser/renderer_host/render_widget_host_unittest.cc b/content/browser/renderer_host/render_widget_host_unittest.cc
index cd3abed..967c814 100644
--- a/content/browser/renderer_host/render_widget_host_unittest.cc
+++ b/content/browser/renderer_host/render_widget_host_unittest.cc
@@ -35,11 +35,9 @@
 #include "ui/gfx/screen.h"
 
 #if defined(USE_AURA)
-#include "content/browser/aura/image_transport_factory.h"
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
 #include "ui/aura/env.h"
 #include "ui/aura/test/test_screen.h"
-#include "ui/compositor/test/test_context_factory.h"
 #endif
 
 #if defined(OS_WIN) || defined(USE_AURA)
@@ -620,8 +618,6 @@ class RenderWidgetHostTest : public testing::Test {
     delegate_.reset(new MockRenderWidgetHostDelegate());
     process_ = new RenderWidgetHostProcess(browser_context_.get());
 #if defined(USE_AURA)
-    ImageTransportFactory::InitializeForUnitTests(
-        scoped_ptr<ui::ContextFactory>(new ui::TestContextFactory));
     aura::Env::CreateInstance();
     screen_.reset(aura::TestScreen::Create());
     gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE, screen_.get());
@@ -642,7 +638,6 @@ class RenderWidgetHostTest : public testing::Test {
 #if defined(USE_AURA)
     aura::Env::DeleteInstance();
     screen_.reset();
-    ImageTransportFactory::Terminate();
 #endif
 
     // Process all pending tasks to avoid leaks.
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index e6fbafa..2478b1b 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -487,7 +487,6 @@ RenderWidgetHostViewAura::RenderWidgetHostViewAura(RenderWidgetHost* host)
 #if defined(OS_WIN)
   plugin_parent_window_ = NULL;
 #endif
-  ImageTransportFactory::GetInstance()->AddObserver(this);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -2141,7 +2140,13 @@ void RenderWidgetHostViewAura::OnAccessibilityEvents(
 }
 
 gfx::GLSurfaceHandle RenderWidgetHostViewAura::GetCompositingSurface() {
-  return ImageTransportFactory::GetInstance()->GetSharedSurfaceHandle();
+  if (shared_surface_handle_.is_null()) {
+    ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
+    shared_surface_handle_ = factory->CreateSharedSurfaceHandle();
+    if (!shared_surface_handle_.is_null())
+      factory->AddObserver(this);
+  }
+  return shared_surface_handle_;
 }
 
 bool RenderWidgetHostViewAura::LockMouse() {
@@ -3203,6 +3208,12 @@ void RenderWidgetHostViewAura::OnLostResources() {
   // are using is becoming invalid. This sends pending ACKs and needs to happen
   // after calling UpdateExternalTexture() which syncs with the impl thread.
   RunOnCommitCallbacks();
+
+  DCHECK(!shared_surface_handle_.is_null());
+  ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
+  factory->DestroySharedSurfaceHandle(shared_surface_handle_);
+  shared_surface_handle_ = factory->CreateSharedSurfaceHandle();
+  host_->CompositingSurfaceUpdated();
   host_->ScheduleComposite();
 }
 
@@ -3214,9 +3225,11 @@ RenderWidgetHostViewAura::~RenderWidgetHostViewAura() {
     paint_observer_->OnViewDestroyed();
   if (touch_editing_client_)
     touch_editing_client_->OnViewDestroyed();
-
-  ImageTransportFactory::GetInstance()->RemoveObserver(this);
-
+  if (!shared_surface_handle_.is_null()) {
+    ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
+    factory->DestroySharedSurfaceHandle(shared_surface_handle_);
+    factory->RemoveObserver(this);
+  }
   window_observer_.reset();
   if (window_->GetDispatcher())
     window_->GetDispatcher()->RemoveRootWindowObserver(this);
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
index 16a4dee..86db864 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.h
+++ b/content/browser/renderer_host/render_widget_host_view_aura.h
@@ -674,6 +674,8 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   gfx::Size last_swapped_surface_size_;
   float last_swapped_surface_scale_factor_;
 
+  gfx::GLSurfaceHandle shared_surface_handle_;
+
   // If non-NULL we're in OnPaint() and this is the supplied canvas.
   gfx::Canvas* paint_canvas_;
 
diff --git a/content/common/gpu/client/gpu_channel_host.cc b/content/common/gpu/client/gpu_channel_host.cc
index 72f80f1..705f4b9d 100644
--- a/content/common/gpu/client/gpu_channel_host.cc
+++ b/content/common/gpu/client/gpu_channel_host.cc
@@ -35,11 +35,12 @@ GpuListenerInfo::~GpuListenerInfo() {}
 // static
 scoped_refptr<GpuChannelHost> GpuChannelHost::Create(
     GpuChannelHostFactory* factory,
+    int gpu_host_id,
     const gpu::GPUInfo& gpu_info,
     const IPC::ChannelHandle& channel_handle) {
   DCHECK(factory->IsMainThread());
   scoped_refptr<GpuChannelHost> host = new GpuChannelHost(
-      factory, gpu_info);
+      factory, gpu_host_id, gpu_info);
   host->Connect(channel_handle);
   return host;
 }
@@ -59,8 +60,10 @@ bool GpuChannelHost::IsValidGpuMemoryBuffer(
 }
 
 GpuChannelHost::GpuChannelHost(GpuChannelHostFactory* factory,
+                               int gpu_host_id,
                                const gpu::GPUInfo& gpu_info)
     : factory_(factory),
+      gpu_host_id_(gpu_host_id),
       gpu_info_(gpu_info) {
   next_transfer_buffer_id_.GetNext();
   next_gpu_memory_buffer_id_.GetNext();
diff --git a/content/common/gpu/client/gpu_channel_host.h b/content/common/gpu/client/gpu_channel_host.h
index 03466ea..52ffb38 100644
--- a/content/common/gpu/client/gpu_channel_host.h
+++ b/content/common/gpu/client/gpu_channel_host.h
@@ -93,6 +93,7 @@ class GpuChannelHost : public IPC::Sender,
   // Must be called on the main thread (as defined by the factory).
   static scoped_refptr<GpuChannelHost> Create(
       GpuChannelHostFactory* factory,
+      int gpu_host_id,
       const gpu::GPUInfo& gpu_info,
       const IPC::ChannelHandle& channel_handle);
 
@@ -149,6 +150,7 @@ class GpuChannelHost : public IPC::Sender,
   void RemoveRoute(int route_id);
 
   GpuChannelHostFactory* factory() const { return factory_; }
+  int gpu_host_id() const { return gpu_host_id_; }
 
   // Returns a handle to the shared memory that can be sent via IPC to the
   // GPU process. The caller is responsible for ensuring it is closed. Returns
@@ -177,6 +179,7 @@ class GpuChannelHost : public IPC::Sender,
  private:
   friend class base::RefCountedThreadSafe<GpuChannelHost>;
   GpuChannelHost(GpuChannelHostFactory* factory,
+                 int gpu_host_id,
                  const gpu::GPUInfo& gpu_info);
   virtual ~GpuChannelHost();
   void Connect(const IPC::ChannelHandle& channel_handle);
@@ -241,6 +244,7 @@ class GpuChannelHost : public IPC::Sender,
   // - |next_gpu_memory_buffer_id_|, atomic type
   // - |proxies_|, protected by |context_lock_|
   GpuChannelHostFactory* const factory_;
+  const int gpu_host_id_;
 
   const gpu::GPUInfo gpu_info_;
 
diff --git a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
index b4fc17a..4c8be5e 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
@@ -477,6 +477,11 @@ void WebGraphicsContext3DCommandBufferImpl::Destroy() {
   host_ = NULL;
 }
 
+// TODO(apatrick,piman): This should be renamed to something clearer.
+int WebGraphicsContext3DCommandBufferImpl::GetGPUProcessID() {
+  return host_.get() ? host_->gpu_host_id() : 0;
+}
+
 gpu::ContextSupport*
 WebGraphicsContext3DCommandBufferImpl::GetContextSupport() {
   return real_gl_.get();
diff --git a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h
index b56c4a4..ca88136 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h
@@ -83,6 +83,10 @@ class WebGraphicsContext3DCommandBufferImpl
 
   virtual ~WebGraphicsContext3DCommandBufferImpl();
 
+  // The following 3 IDs let one uniquely identify this context.
+  // Gets the GPU process ID for this context.
+  int GetGPUProcessID();
+
   CommandBufferProxyImpl* GetCommandBufferProxy() {
     return command_buffer_.get();
   }
diff --git a/content/common/gpu/gpu_messages.h b/content/common/gpu/gpu_messages.h
index 9e25bc9..936a8a0 100644
--- a/content/common/gpu/gpu_messages.h
+++ b/content/common/gpu/gpu_messages.h
@@ -215,6 +215,7 @@ IPC_ENUM_TRAITS(gfx::SurfaceType)
 IPC_STRUCT_TRAITS_BEGIN(gfx::GLSurfaceHandle)
   IPC_STRUCT_TRAITS_MEMBER(handle)
   IPC_STRUCT_TRAITS_MEMBER(transport_type)
+  IPC_STRUCT_TRAITS_MEMBER(parent_gpu_process_id)
   IPC_STRUCT_TRAITS_MEMBER(parent_client_id)
 IPC_STRUCT_TRAITS_END()
 
diff --git a/content/public/browser/render_process_host.h b/content/public/browser/render_process_host.h
index dd2fab6..6ddf375 100644
--- a/content/public/browser/render_process_host.h
+++ b/content/public/browser/render_process_host.h
@@ -201,6 +201,11 @@ class CONTENT_EXPORT RenderProcessHost : public IPC::Sender,
   // 10 milliseconds.
   virtual base::TimeDelta GetChildProcessIdleTime() const = 0;
 
+  // Signals that a compositing surface has been updated after a lost context
+  // event, so that we can process requests from the renderer to create contexts
+  // with that surface.
+  virtual void SurfaceUpdated(int32 surface_id) = 0;
+
   // Called to resume the requests for a view created through window.open that
   // were initially blocked.
   virtual void ResumeRequestsForView(int route_id) = 0;
diff --git a/content/public/test/mock_render_process_host.cc b/content/public/test/mock_render_process_host.cc
index eadf339..c579b66 100644
--- a/content/public/test/mock_render_process_host.cc
+++ b/content/public/test/mock_render_process_host.cc
@@ -250,6 +250,9 @@ base::TimeDelta MockRenderProcessHost::GetChildProcessIdleTime() const {
   return base::TimeDelta::FromMilliseconds(0);
 }
 
+void MockRenderProcessHost::SurfaceUpdated(int32 surface_id) {
+}
+
 void MockRenderProcessHost::ResumeRequestsForView(int route_id) {
 }
 
diff --git a/content/public/test/mock_render_process_host.h b/content/public/test/mock_render_process_host.h
index 60ebef2..c9f20fa 100644
--- a/content/public/test/mock_render_process_host.h
+++ b/content/public/test/mock_render_process_host.h
@@ -73,6 +73,7 @@ class MockRenderProcessHost : public RenderProcessHost {
   virtual void AddFilter(BrowserMessageFilter* filter) OVERRIDE;
   virtual bool FastShutdownForPageCount(size_t count) OVERRIDE;
   virtual base::TimeDelta GetChildProcessIdleTime() const OVERRIDE;
+  virtual void SurfaceUpdated(int32 surface_id) OVERRIDE;
   virtual void ResumeRequestsForView(int route_id) OVERRIDE;
 #if defined(ENABLE_WEBRTC)
   virtual void EnableAecDump(const base::FilePath& file) OVERRIDE;
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 9df1218..9b85289 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -1213,7 +1213,8 @@ GpuChannelHost* RenderThreadImpl::EstablishGpuChannelSync(
   io_message_loop_proxy_ = ChildProcess::current()->io_message_loop_proxy();
   shutdown_event_ = ChildProcess::current()->GetShutDownEvent();
 
-  gpu_channel_ = GpuChannelHost::Create(this, gpu_info, channel_handle);
+  gpu_channel_ = GpuChannelHost::Create(
+      this, 0, gpu_info, channel_handle);
   return gpu_channel_.get();
 }