Make render pipeline throttling opt-in

third_party/WebKit/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 21 matching lines @@
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
 
 static DocumentLifecycle::DeprecatedTransition* s_deprecatedTransitionStack = 0;
 
 // TODO(skyostil): Come up with a better way to store cross-frame lifecycle
 // related data to avoid this being a global setting.
-static unsigned s_preventThrottlingCount = 0;
+static unsigned s_allowThrottlingCount = 0;
 
 DocumentLifecycle::Scope::Scope(DocumentLifecycle& lifecycle, State finalState)
     : m_lifecycle(lifecycle)
     , m_finalState(finalState)
 {
 }
 
 DocumentLifecycle::Scope::~Scope()
 {
     m_lifecycle.advanceTo(m_finalState);
 }
 
 DocumentLifecycle::DeprecatedTransition::DeprecatedTransition(State from, State to)
     : m_previous(s_deprecatedTransitionStack)
     , m_from(from)
     , m_to(to)
 {
     s_deprecatedTransitionStack = this;
 }
 
 DocumentLifecycle::DeprecatedTransition::~DeprecatedTransition()
 {
     s_deprecatedTransitionStack = m_previous;
 }
 
-DocumentLifecycle::PreventThrottlingScope::PreventThrottlingScope(DocumentLifecycle& lifecycle)
+DocumentLifecycle::AllowThrottlingScope::AllowThrottlingScope(DocumentLifecycle& lifecycle)
 {
-    s_preventThrottlingCount++;
+    s_allowThrottlingCount++;
 }
 
-DocumentLifecycle::PreventThrottlingScope::~PreventThrottlingScope()
+DocumentLifecycle::AllowThrottlingScope::~AllowThrottlingScope()
 {
-    ASSERT(s_preventThrottlingCount > 0);
-    s_preventThrottlingCount--;
+    ASSERT(s_allowThrottlingCount > 0);
+    s_allowThrottlingCount--;
 }
 
 DocumentLifecycle::DocumentLifecycle()
     : m_state(Uninitialized)
     , m_detachCount(0)
 {
 }
 
 DocumentLifecycle::~DocumentLifecycle()
 {
@@ skipping 189 matching lines @@
     ASSERT(state == VisualUpdatePending || state == StyleClean || state == LayoutClean);
     if (m_state <= state)
         return;
     ASSERT_WITH_MESSAGE(canRewindTo(state),
         "Cannot rewind document lifecycle from %s to %s.", stateAsDebugString(m_state), stateAsDebugString(state));
     m_state = state;
 }
 
 bool DocumentLifecycle::throttlingAllowed() const
 {
-    return !s_preventThrottlingCount;
+    return s_allowThrottlingCount;
 }
 
 #if ENABLE(ASSERT)
 #define DEBUG_STRING_CASE(StateName) \
     case StateName: return #StateName
 
 const char* DocumentLifecycle::stateAsDebugString(const State state)
 {
     switch (state) {
         DEBUG_STRING_CASE(Uninitialized);
@@ skipping 19 matching lines @@
         DEBUG_STRING_CASE(Stopped);
         DEBUG_STRING_CASE(Disposed);
     }
 
     ASSERT_NOT_REACHED();
     return "Unknown";
 }
 #endif
 
 } // namespace blink