Fire visibilityChange event on out-of-process iframes.

third_party/WebKit/public/web/WebFrameWidget.h

Index: third_party/WebKit/public/web/WebFrameWidget.h
diff --git a/third_party/WebKit/public/web/WebFrameWidget.h b/third_party/WebKit/public/web/WebFrameWidget.h
index 5607bbecc4489fde8dd509920c9b7a29d9a8aa24..f38e61ee6a155cb0238455f6239b9f4f645a8ecf 100644
--- a/third_party/WebKit/public/web/WebFrameWidget.h
+++ b/third_party/WebKit/public/web/WebFrameWidget.h
@@ -53,7 +53,7 @@ public:
     // We still track page-level visibility, but additionally we need to notify a WebFrameWidget
     // when its owning RenderWidget receives a Show or Hide directive, so that it knows whether
     // it needs to draw or not.
-    virtual void setVisibilityState(WebPageVisibilityState visibilityState, bool isInitialState) { }
+    virtual void setVisibilityState(WebPageVisibilityState visibilityState) {}
 
     // Makes the WebFrameWidget transparent.  This is useful if you want to have
     // some custom background rendered behind it.