Throttle rendering pipeline for invisible frames

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 20 matching lines @@
 #include "config.h"
 #include "core/dom/DocumentLifecycle.h"
 
 #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 DocumentLifecycle::ThrottlingMode s_throttlingMode = DocumentLifecycle::ThrottlingMode::Allow;

[esprehn, 2015/10/14 22:09:46]

unsigned s_throttleCount

[Sami, 2015/10/16 16:48:08]

Done (made it s_throttlingDisallowCount since that's really what the scopes are
doing.)

+
 DocumentLifecycle::Scope::Scope(DocumentLifecycle& lifecycle, State finalState)
     : m_lifecycle(lifecycle)
     , m_finalState(finalState)
 {
 }
 
 DocumentLifecycle::Scope::~Scope()
 {
     m_lifecycle.advanceTo(m_finalState);
 }
@@ skipping 233 matching lines @@
 void DocumentLifecycle::ensureStateAtMost(State state)
 {
     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;
 }
 
+void DocumentLifecycle::setThrottlingMode(ThrottlingMode throttlingMode)
+{
+    s_throttlingMode = throttlingMode;
+}
+
+DocumentLifecycle::ThrottlingMode DocumentLifecycle::throttlingMode() const
+{
+    return s_throttlingMode;
+}
+
 #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);
         DEBUG_STRING_CASE(Inactive);
         DEBUG_STRING_CASE(VisualUpdatePending);
@@ skipping 19 matching lines @@
         DEBUG_STRING_CASE(Stopped);
         DEBUG_STRING_CASE(Disposed);
     }
 
     ASSERT_NOT_REACHED();
     return "Unknown";
 }
 #endif
 
 }