Throttle rendering pipeline for invisible iframes

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 7d7ae970d4ac9b0388845d1e5d457848a017e079..44a298fcc3f41498335e826e338cb2a503460174 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -1883,6 +1883,9 @@ void WebViewImpl::beginFrame(const WebBeginFrameArgs& frameTime)
     // FIXME: This should probably be using the local root?
     if (m_page->mainFrame()->isLocalFrame())
         PageWidgetDelegate::animate(*m_page, validFrameTime.lastFrameTimeMonotonic, *m_page->deprecatedLocalMainFrame());
+
+    // HACK: simulate the commit signal for layout tests
+    //Platform::current()->mainThread()->postTask(FROM_HERE, bind(&WebViewImpl::didCommitCompositorFrame, this));
 }
 
 void WebViewImpl::layout()
@@ -1931,6 +1934,14 @@ void WebViewImpl::paint(WebCanvas* canvas, const WebRect& rect)
     Platform::current()->histogramCustomCounts("Renderer4.SoftwarePaintMegapixPerSecond", pixelsPerSec / 1000000, 10, 210, 30);
 }
 
+void WebViewImpl::didCommitCompositorFrame()
+{
+    if (!mainFrameImpl() || !mainFrameImpl()->frameView())
+        return;
+    FrameView* view = mainFrameImpl()->frameView();
+    view->updateThrottling();
+}
+
 #if OS(ANDROID)
 void WebViewImpl::paintCompositedDeprecated(WebCanvas* canvas, const WebRect& rect)
 {