Make Blink stop scheduling its own Layout, and use the compositor's timer instead

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 1700 matching lines @@
     }
 
     if (Element* oe = ownerElement())
         oe->document()->updateLayout();
 
     updateStyleIfNeeded();
 
     StackStats::LayoutCheckPoint layoutCheckPoint;
 
     // Only do a layout if changes have occurred that make it necessary.
-    if (frameView && renderer() && (frameView->layoutPending() || renderer()->needsLayout()))
+    if (frameView && renderer() && (frameView->layoutIsScheduledWithEmbedder() || renderer()->needsLayout()))
         frameView->layout();
 
     // FIXME: Using a Task doesn't look a good idea.
     if (m_focusedElement && !m_didPostCheckFocusedElementTask) {
         postTask(CheckFocusedElementTask::create());
         m_didPostCheckFocusedElementTask = true;
     }
 }
 
 // FIXME: This is a bad idea and needs to be removed eventually.
@@ skipping 577 matching lines @@
     //
     //    (a) Only schedule a layout once the stylesheets are loaded.
     //    (b) Only schedule layout once we have a body element.
 
     return (haveStylesheetsLoaded() && body())
         || (documentElement() && !isHTMLHtmlElement(documentElement()));
 }
 
 bool Document::shouldParserYieldAgressivelyBeforeScriptExecution()
 {
-    return view() && view()->layoutPending() && !minimumLayoutDelay();
+    return view() && view()->layoutIsScheduledWithEmbedder() && !minimumLayoutDelay();
 }
 
+// FIXME: I believe this whole function is useless.
 int Document::minimumLayoutDelay()
 {
     if (m_overMinimumLayoutThreshold)
         return 0;
 
     int elapsed = elapsedTime();
     m_overMinimumLayoutThreshold = elapsed > cLayoutScheduleThreshold;
 
     // We'll want to schedule the timer to fire at the minimum layout threshold.
     return max(0, cLayoutScheduleThreshold - elapsed);
@@ skipping 2755 matching lines @@
 {
     return DocumentLifecycleNotifier::create(this);
 }
 
 DocumentLifecycleNotifier* Document::lifecycleNotifier()
 {
     return static_cast<DocumentLifecycleNotifier*>(ScriptExecutionContext::lifecycleNotifier());
 }
 
 } // namespace WebCore