Refactor mixed content checks against the top frame into MixedContentChecker.

Source/core/loader/PingLoader.cpp

Index: Source/core/loader/PingLoader.cpp
diff --git a/Source/core/loader/PingLoader.cpp b/Source/core/loader/PingLoader.cpp
index 8bc691a594ad59ebc3af89be2bc29b4f51750618..b8a39ccf9c2eb5f8fb6d8cca4b0d63a06160716a 100644
--- a/Source/core/loader/PingLoader.cpp
+++ b/Source/core/loader/PingLoader.cpp
@@ -122,9 +122,6 @@ void PingLoader::start(LocalFrame* frame, ResourceRequest& request, const FetchI
 {
     if (!frame->loader().mixedContentChecker()->canRunInsecureContent(frame->document()->securityOrigin(), request.url()))

[Mike West, 2014/06/30 12:24:37]

The PingLoader check is here. We were previously doing two checks: one for the
current frame, one for the top frame. Now we're wrapping that up into the
MixedContentChecker.

         return;
-    Frame* top = frame->tree().top();
-    if (top != frame && !toLocalFrame(top)->loader().mixedContentChecker()->canRunInsecureContent(toLocalFrame(top)->document()->securityOrigin(), request.url()))
-        return;
 
     OwnPtr<PingLoader> pingLoader = adoptPtr(new PingLoader(frame, request, initiatorInfo, credentialsAllowed));