Mac ÜC: Make resize smooth

content/browser/gpu/gpu_process_host.cc

Index: content/browser/gpu/gpu_process_host.cc
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index 6e3b4390d7725d9f150e8ee7c55d9330b6a3c24f..a7c3aa703d3acd057cb54484394b309f3a7b6f72 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -852,39 +852,49 @@ void GpuProcessHost::OnAcceleratedSurfaceBuffersSwapped(
 
   gfx::AcceleratedWidget native_widget =
       GpuSurfaceTracker::Get()->AcquireNativeWidget(params.surface_id);
-  if (native_widget) {
-    RenderWidgetHelper::OnNativeSurfaceBuffersSwappedOnIOThread(this, params);
-    return;
-  }
 
-  gfx::GLSurfaceHandle surface_handle =
-      GpuSurfaceTracker::Get()->GetSurfaceHandle(params.surface_id);
-  // Compositor window is always gfx::kNullPluginWindow.
-  // TODO(jbates) http://crbug.com/105344 This will be removed when there are no
-  // plugin windows.
-  if (surface_handle.handle != gfx::kNullPluginWindow ||
-      surface_handle.transport_type == gfx::TEXTURE_TRANSPORT) {
-    RouteOnUIThread(GpuHostMsg_AcceleratedSurfaceBuffersSwapped(params));
-    return;
+  // Retrieve the render widget helper to forward this message to on the UI
+  // thread.
+  RenderWidgetHelper* helper = NULL;
+  int render_widget_id = 0;
+  if (native_widget) {
+    int render_process_id = 0;
+    // TODO(ccameron): The render process and widget IDs have a race between
+    // the UI and the IO threads, and may potentially be wrong. Move the
+    // functionality in RenderProcessHost::WaitForBackingStoreMsg to a place
+    // where it can accept IPCs from all renderers (rather than this hack where
+    // we fake the render process and widget ID of a renderer for the browser).
+    // http://crbug.com/392031
+    if (RenderWidgetHelper::GetRenderWidgetIDForWidget(
+            native_widget, &render_process_id, &render_widget_id)) {
+      helper = RenderWidgetHelper::FromProcessHostID(render_process_id);
+    }
+  } else {
+    int render_process_id = 0;
+    if (GpuSurfaceTracker::Get()->GetRenderWidgetIDForSurface(
+        params.surface_id, &render_process_id, &render_widget_id)) {
+      helper = RenderWidgetHelper::FromProcessHostID(render_process_id);
+    }
   }
 
-  AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
-  ack_params.sync_point = 0;
-
-  int render_process_id = 0;
-  int render_widget_id = 0;
-  if (!GpuSurfaceTracker::Get()->GetRenderWidgetIDForSurface(
-      params.surface_id, &render_process_id, &render_widget_id)) {
+  // If this is not targetting a native widget and we don't find a helper, then
+  // ack immediately and ignore the message.
+  if (!helper && !native_widget) {
+    AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
+    ack_params.sync_point = 0;
     Send(new AcceleratedSurfaceMsg_BufferPresented(params.route_id,
                                                    ack_params));
     return;
   }
-  RenderWidgetHelper* helper =
-      RenderWidgetHelper::FromProcessHostID(render_process_id);
-  if (!helper) {
+
+  // If this is targetting a native widget, then ack the swap immediately to
+  // avoid introducing a deadlock between the browser and GPU processes (rate
+  // limiting is done through the compositor).
+  if (native_widget) {
+    AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
+    ack_params.sync_point = 0;
     Send(new AcceleratedSurfaceMsg_BufferPresented(params.route_id,
                                                    ack_params));
-    return;
   }
 
   // Pass the SwapBuffers on to the RenderWidgetHelper to wake up the UI thread
@@ -892,6 +902,7 @@ void GpuProcessHost::OnAcceleratedSurfaceBuffersSwapped(
   // will forward to the RenderWidgetHostView via RenderProcessHostImpl and
   // RenderWidgetHostImpl.
   ViewHostMsg_CompositorSurfaceBuffersSwapped_Params view_params;
+  view_params.use_native_widget = native_widget;
   view_params.surface_id = params.surface_id;
   view_params.surface_handle = params.surface_handle;
   view_params.route_id = params.route_id;
@@ -899,9 +910,18 @@ void GpuProcessHost::OnAcceleratedSurfaceBuffersSwapped(
   view_params.scale_factor = params.scale_factor;
   view_params.gpu_process_host_id = host_id_;
   view_params.latency_info = params.latency_info;
-  helper->DidReceiveBackingStoreMsg(ViewHostMsg_CompositorSurfaceBuffersSwapped(
-      render_widget_id,
-      view_params));
+  if (helper) {
+    helper->DidReceiveBackingStoreMsg(
+        ViewHostMsg_CompositorSurfaceBuffersSwapped(
+            render_widget_id,
+            view_params));
+  } else if (native_widget) {
+    BrowserThread::PostTask(
+        BrowserThread::UI,
+        FROM_HERE,
+        base::Bind(&RenderWidgetHelper::OnNativeSurfaceBuffersSwappedOnUIThread,
+                       view_params));
+  }
 }
 #endif  // OS_MACOSX