Throttle rendering pipeline for invisible frames

third_party/WebKit/Source/core/dom/DocumentLifecycle.h

Index: third_party/WebKit/Source/core/dom/DocumentLifecycle.h
diff --git a/third_party/WebKit/Source/core/dom/DocumentLifecycle.h b/third_party/WebKit/Source/core/dom/DocumentLifecycle.h
index d111b1d694812eb3fb15ba74d66621215011e02b..5cce130320b03e9255f4428a22738f1276a0a25b 100644
--- a/third_party/WebKit/Source/core/dom/DocumentLifecycle.h
+++ b/third_party/WebKit/Source/core/dom/DocumentLifecycle.h
@@ -134,6 +134,17 @@ public:
         DocumentLifecycle& m_documentLifecycle;
     };
 
+    class PreventThrottlingScope {
+        STACK_ALLOCATED();
+        WTF_MAKE_NONCOPYABLE(PreventThrottlingScope);
+    public:
+        PreventThrottlingScope(DocumentLifecycle&);
+        ~PreventThrottlingScope();
+
+    private:
+        DocumentLifecycle& m_lifecycle;
+    };
+
     DocumentLifecycle();
     ~DocumentLifecycle();
 
@@ -157,6 +168,8 @@ public:
         m_detachCount--;
     }
 
+    bool throttlingAllowed() const;
+
 #if ENABLE(ASSERT)
     static const char* stateAsDebugString(const State);
 #endif
@@ -167,6 +180,9 @@ private:
     bool canRewindTo(State) const;
 #endif
 
+    void incrementPreventThrottlingCount();
+    void decrementPreventThrottlingCount();
+
     State m_state;
     int m_detachCount;
 };