Allow ui::Compositor to disable commits 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 28 matching lines @@
 
 }  // namespace
 
 BrowserCompositorMac::BrowserCompositorMac()
     : accelerated_widget_mac_(
           new ui::AcceleratedWidgetMac(WidgetNeedsGLFinishWorkaround())),
       compositor_(
           accelerated_widget_mac_->accelerated_widget(),
           content::GetContextFactory(),
           RenderWidgetResizeHelper::Get()->task_runner()) {
+  compositor_.SetLocksWillTimeOut(false);
+  compositor_suspended_lock_ = compositor_.GetCompositorLock();

[danakj, 2015/03/12 00:07:15]

nit: Call Suspend() ?

[ccameron, 2015/03/12 01:01:34]

Done.

 }
 
 BrowserCompositorMac::~BrowserCompositorMac() {}
 
+void BrowserCompositorMac::Suspend() {
+  compositor_suspended_lock_ = compositor_.GetCompositorLock();
+}
+
+void BrowserCompositorMac::Unsuspend() {
+  compositor_suspended_lock_ = NULL;

[danakj, 2015/03/12 00:07:15]

nullptr

[ccameron, 2015/03/12 01:01:34]

Done.

+}
+
 // 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) {
@@ skipping 31 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