Mac: Fix black flashing during tab switch

content/browser/compositor/browser_compositor_view_mac.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/compositor/browser_compositor_view_mac.h"
 
 #include "base/lazy_instance.h"
 #include "base/trace_event/trace_event.h"
 #include "content/browser/compositor/image_transport_factory.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
@@ skipping 30 matching lines @@
 
 BrowserCompositorMac::BrowserCompositorMac()
     : accelerated_widget_mac_(
           new ui::AcceleratedWidgetMac(WidgetNeedsGLFinishWorkaround())),
       compositor_(
           accelerated_widget_mac_->accelerated_widget(),
           content::GetContextFactory(),
           RenderWidgetResizeHelper::Get()->task_runner()) {
   compositor_.SetLocksWillTimeOut(false);
   Suspend();
+  compositor_.AddObserver(this);
 }
 
-BrowserCompositorMac::~BrowserCompositorMac() {}
+BrowserCompositorMac::~BrowserCompositorMac() {
+  compositor_.RemoveObserver(this);
+}
 
 void BrowserCompositorMac::Suspend() {
   compositor_suspended_lock_ = compositor_.GetCompositorLock();
 }
 
 void BrowserCompositorMac::Unsuspend() {
   compositor_suspended_lock_ = nullptr;
 }
 
+void BrowserCompositorMac::OnCompositingDidCommit(
+    ui::Compositor* compositor_that_did_commit) {
+  DCHECK_EQ(compositor_that_did_commit, compositor());
+  content::ImageTransportFactory::GetInstance()
+      ->SetCompositorSuspendedForRecycle(compositor(), false);
+}
+
 // static
 scoped_ptr<BrowserCompositorMac> BrowserCompositorMac::Create() {
   if (g_recyclable_browser_compositor.Get())
     return g_recyclable_browser_compositor.Get().Pass();
   return scoped_ptr<BrowserCompositorMac>(new BrowserCompositorMac).Pass();
 }
 
 // static
 void BrowserCompositorMac::Recycle(
     scoped_ptr<BrowserCompositorMac> compositor) {
   DCHECK(compositor);
-  content::ImageTransportFactory::GetInstance()->OnCompositorRecycled(
-      compositor->compositor());
+  content::ImageTransportFactory::GetInstance()
+      ->SetCompositorSuspendedForRecycle(compositor->compositor(), true);
 
   // It is an error to have a browser compositor continue to exist after
   // shutdown.
   CHECK(!g_has_shut_down);
 
   // Make this BrowserCompositorMac recyclable for future instances.
   g_recyclable_browser_compositor.Get().swap(compositor);
 
   // If there are no placeholders allocated, destroy the recyclable
   // BrowserCompositorMac that we just populated.
@@ skipping 18 matching lines @@
   DCHECK_GT(g_placeholder_count, 0u);
   g_placeholder_count -= 1;
 
   // If there are no placeholders allocated, destroy the recyclable
   // BrowserCompositorMac.
   if (!g_placeholder_count)
     g_recyclable_browser_compositor.Get().reset();
 }
 
 }  // namespace content