Fire visibilityChange event on out-of-process iframes.

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

Index: third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
index 232f3c593beb414be2093ec2270a1dda1909f84b..415045dfe4b84fc9cdc4917fec23f1fead2cffd7 100644
--- a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
+++ b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
@@ -1807,7 +1807,7 @@ WebLocalFrameImpl* WebLocalFrameImpl::localRoot()
     // when the WebLocalFrame exists but the core LocalFrame does not.
     // TODO(alexmos, dcheng): Clean this up to only calculate this in one place.
     WebLocalFrameImpl* localRoot = this;
-    while (!localRoot->frameWidget())
+    while (localRoot->parent() && localRoot->parent()->isWebLocalFrame())
         localRoot = toWebLocalFrameImpl(localRoot->parent());
     return localRoot;
 }