Throttle rendering pipeline for invisible frames

third_party/WebKit/Source/core/layout/LayoutView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 69 matching lines @@
 LayoutView::~LayoutView()
 {
 }
 
 bool LayoutView::hitTest(HitTestResult& result)
 {
     // We have to recursively update layout/style here because otherwise, when the hit test recurses
     // into a child document, it could trigger a layout on the parent document, which can destroy PaintLayer
     // that are higher up in the call stack, leading to crashes.
     // Note that Document::updateLayout calls its parent's updateLayout.
+    DocumentLifecycle::PreventThrottlingScope preventThrottling(document().lifecycle());
     frameView()->updateLifecycleToCompositingCleanPlusScrolling();
     return hitTestNoLifecycleUpdate(result);
 }
 
 bool LayoutView::hitTestNoLifecycleUpdate(HitTestResult& result)
 {
     TRACE_EVENT_BEGIN0("blink,devtools.timeline", "HitTest");
     m_hitTestCount++;
 
     ASSERT(!result.hitTestLocation().isRectBasedTest() || result.hitTestRequest().listBased());
@@ skipping 838 matching lines @@
     return viewHeight(IncludeScrollbars) / scale;
 }
 
 void LayoutView::willBeDestroyed()
 {
     LayoutBlockFlow::willBeDestroyed();
     m_compositor.clear();
 }
 
 } // namespace blink