Replaces uses of the WGC3DSwapBuffersClient with LTHSingleThreadClient

This converts users of the WebGraphicsContext3DSwapBuffersClient mechanism
over to using callbacks from cc::LayerTreeHostSingleThreadClient instead.
This mechanism is a way to implement flow control when using single threaded
compositing by keeping track of the number of pending SwapBuffers calls.
WGC3DSwapBuffersClient hooked into the context directly to observer these
calls, but intercepted the calls at an awkward place. This instead gets
callbacks directly from the compositor when using the single threaded path.

R=piman
BUG=181120

Review URL: https://codereview.chromium.org/59033012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233777 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 9 insertions, 78 deletions

diff --git a/content/browser/aura/gpu_process_transport_factory.cc b/content/browser/aura/gpu_process_transport_factory.cc
index f958ae9..4b8e8ef 100644
--- a/content/browser/aura/gpu_process_transport_factory.cc
+++ b/content/browser/aura/gpu_process_transport_factory.cc
@@ -46,7 +46,6 @@ namespace content {
 
 struct GpuProcessTransportFactory::PerCompositorData {
   int surface_id;
-  scoped_ptr<CompositorSwapClient> swap_client;
 #if defined(OS_WIN)
   scoped_ptr<AcceleratedSurface> accelerated_surface;
 #endif
@@ -143,48 +142,6 @@ class ImageTransportClientTexture : public OwnedTexture {
   DISALLOW_COPY_AND_ASSIGN(ImageTransportClientTexture);
 };
 
-class CompositorSwapClient
-    : public base::SupportsWeakPtr<CompositorSwapClient>,
-      public WebGraphicsContext3DSwapBuffersClient {
- public:
-  CompositorSwapClient(ui::Compositor* compositor,
-                       GpuProcessTransportFactory* factory)
-      : compositor_(compositor),
-        factory_(factory) {
-  }
-
-  virtual ~CompositorSwapClient() {
-  }
-
-  virtual void OnViewContextSwapBuffersPosted() OVERRIDE {
-    compositor_->OnSwapBuffersPosted();
-  }
-
-  virtual void OnViewContextSwapBuffersComplete() OVERRIDE {
-    compositor_->OnSwapBuffersComplete();
-  }
-
-  virtual void OnViewContextSwapBuffersAborted() OVERRIDE {
-    // Recreating contexts directly from here causes issues, so post a task
-    // instead.
-    // TODO(piman): Fix the underlying issues.
-    base::MessageLoop::current()->PostTask(
-        FROM_HERE,
-        base::Bind(&CompositorSwapClient::OnLostContext, this->AsWeakPtr()));
-  }
-
- private:
-  void OnLostContext() {
-    factory_->OnLostContext(compositor_);
-    // Note: previous line destroyed this. Don't access members from now on.
-  }
-
-  ui::Compositor* compositor_;
-  GpuProcessTransportFactory* factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(CompositorSwapClient);
-};
-
 GpuProcessTransportFactory::GpuProcessTransportFactory()
     : callback_factory_(this) {
   output_surface_proxy_ = new BrowserCompositorOutputSurfaceProxy(
@@ -200,8 +157,7 @@ GpuProcessTransportFactory::~GpuProcessTransportFactory() {
 
 scoped_ptr<WebGraphicsContext3DCommandBufferImpl>
 GpuProcessTransportFactory::CreateOffscreenCommandBufferContext() {
-  base::WeakPtr<WebGraphicsContext3DSwapBuffersClient> swap_client;
-  return CreateContextCommon(swap_client, 0);
+  return CreateContextCommon(0);
 }
 
 scoped_ptr<cc::SoftwareOutputDevice> CreateSoftwareOutputDevice(
@@ -228,17 +184,12 @@ scoped_ptr<cc::OutputSurface> GpuProcessTransportFactory::CreateOutputSurface(
     data = CreatePerCompositorData(compositor);
 
   scoped_refptr<ContextProviderCommandBuffer> context_provider;
-  base::WeakPtr<WebGraphicsContext3DSwapBuffersClient> swap_client_weak_ptr;
-  if (data->swap_client)
-    swap_client_weak_ptr = data->swap_client->AsWeakPtr();
 
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (!command_line->HasSwitch(switches::kUIEnableSoftwareCompositing)) {
     context_provider = ContextProviderCommandBuffer::Create(
-        GpuProcessTransportFactory::CreateContextCommon(
-            swap_client_weak_ptr,
-            data->surface_id),
-            "Compositor");
+        GpuProcessTransportFactory::CreateContextCommon(data->surface_id),
+        "Compositor");
   }
 
   UMA_HISTOGRAM_BOOLEAN("Aura.CreatedGpuBrowserCompositor", !!context_provider);
@@ -454,18 +405,6 @@ GpuProcessTransportFactory::SharedMainThreadContextProvider() {
   return shared_main_thread_contexts_;
 }
 
-void GpuProcessTransportFactory::OnLostContext(ui::Compositor* compositor) {
-  LOG(ERROR) << "Lost UI compositor context.";
-  PerCompositorData* data = per_compositor_data_[compositor];
-  DCHECK(data);
-
-  // Prevent callbacks from other contexts in the same share group from
-  // calling us again.
-  if (data->swap_client.get())
-    data->swap_client.reset(new CompositorSwapClient(compositor, this));
-  compositor->OnSwapBuffersAborted();
-}
-
 GpuProcessTransportFactory::PerCompositorData*
 GpuProcessTransportFactory::CreatePerCompositorData(
     ui::Compositor* compositor) {
@@ -476,8 +415,6 @@ GpuProcessTransportFactory::CreatePerCompositorData(
 
   PerCompositorData* data = new PerCompositorData;
   data->surface_id = tracker->AddSurfaceForNativeWidget(widget);
-  if (!ui::Compositor::WasInitializedWithThread())
-    data->swap_client.reset(new CompositorSwapClient(compositor, this));
 #if defined(OS_WIN)
   if (GpuDataManagerImpl::GetInstance()->IsUsingAcceleratedSurface())
     data->accelerated_surface.reset(new AcceleratedSurface(widget));
@@ -492,9 +429,7 @@ GpuProcessTransportFactory::CreatePerCompositorData(
 }
 
 scoped_ptr<WebGraphicsContext3DCommandBufferImpl>
-GpuProcessTransportFactory::CreateContextCommon(
-    const base::WeakPtr<WebGraphicsContext3DSwapBuffersClient>& swap_client,
-    int surface_id) {
+GpuProcessTransportFactory::CreateContextCommon(int surface_id) {
   if (!GpuDataManagerImpl::GetInstance()->CanUseGpuBrowserCompositor())
     return scoped_ptr<WebGraphicsContext3DCommandBufferImpl>();
   blink::WebGraphicsContext3D::Attributes attrs;
@@ -503,9 +438,10 @@ GpuProcessTransportFactory::CreateContextCommon(
   attrs.stencil = false;
   attrs.antialias = false;
   attrs.noAutomaticFlushes = true;
+  CauseForGpuLaunch cause =
+      CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE;
   scoped_refptr<GpuChannelHost> gpu_channel_host(
-      BrowserGpuChannelHostFactory::instance()->EstablishGpuChannelSync(
-          CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE));
+      BrowserGpuChannelHostFactory::instance()->EstablishGpuChannelSync(cause));
   if (!gpu_channel_host)
     return scoped_ptr<WebGraphicsContext3DCommandBufferImpl>();
   GURL url("chrome://gpu/GpuProcessTransportFactory::CreateContextCommon");
@@ -515,7 +451,6 @@ GpuProcessTransportFactory::CreateContextCommon(
           surface_id,
           url,
           gpu_channel_host.get(),
-          swap_client,
           use_echo_for_swap_ack,
           attrs,
           false,
diff --git a/content/browser/aura/gpu_process_transport_factory.h b/content/browser/aura/gpu_process_transport_factory.h
index dd6e79a..36ebb00 100644
--- a/content/browser/aura/gpu_process_transport_factory.h
+++ b/content/browser/aura/gpu_process_transport_factory.h
@@ -22,7 +22,6 @@ class CompositorSwapClient;
 class ContextProviderCommandBuffer;
 class ReflectorImpl;
 class WebGraphicsContext3DCommandBufferImpl;
-class WebGraphicsContext3DSwapBuffersClient;
 
 class GpuProcessTransportFactory
     : public ui::ContextFactory,
@@ -68,15 +67,12 @@ class GpuProcessTransportFactory
   virtual void RemoveObserver(
       ImageTransportFactoryObserver* observer) OVERRIDE;
 
-  void OnLostContext(ui::Compositor* compositor);
-
  private:
   struct PerCompositorData;
 
   PerCompositorData* CreatePerCompositorData(ui::Compositor* compositor);
-  scoped_ptr<WebGraphicsContext3DCommandBufferImpl> CreateContextCommon(
-      const base::WeakPtr<WebGraphicsContext3DSwapBuffersClient>& swap_client,
-      int surface_id);
+  scoped_ptr<WebGraphicsContext3DCommandBufferImpl>
+      CreateContextCommon(int surface_id);
 
   void OnLostMainThreadSharedContextInsideCallback();
   void OnLostMainThreadSharedContext();