Throttle rendering pipeline for invisible iframes

Source/core/dom/DocumentLifecycle.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 47 matching lines @@
 }
 
 DocumentLifecycle::DeprecatedTransition::~DeprecatedTransition()
 {
     s_deprecatedTransitionStack = m_previous;
 }
 
 DocumentLifecycle::DocumentLifecycle()
     : m_state(Uninitialized)
     , m_detachCount(0)
+    , m_throttlingMode(ThrottlingMode::Disallow)
 {
 }
 
 DocumentLifecycle::~DocumentLifecycle()
 {
 }
 
 #if ENABLE(ASSERT)
 
 bool DocumentLifecycle::canAdvanceTo(State nextState) const
@@ skipping 181 matching lines @@
 
 void DocumentLifecycle::ensureStateAtMost(State state)
 {
     ASSERT(state == VisualUpdatePending || state == StyleClean || state == LayoutClean);
     if (m_state <= state)
         return;
     ASSERT(canRewindTo(state));
     m_state = state;
 }
 
+void DocumentLifecycle::setThrottlingMode(ThrottlingMode throttlingMode)
+{
+    m_throttlingMode = throttlingMode;
 }
+
+DocumentLifecycle::ThrottlingMode DocumentLifecycle::throttlingMode() const
+{
+    return m_throttlingMode;
+}
+
+}