Consolidate functions for updating state after a security origin change.

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index 86d7b44daabe34a73d62b919c7f157d825feb549..6b5574762384710a25d50f80cfe1ea3656bc96f6 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -1068,7 +1068,6 @@ bool FrameLoader::prepareForCommit()
     if (m_frame->document())
         m_frame->document()->detach();
     m_documentLoader = m_provisionalDocumentLoader.release();
-    m_frame->updateFrameSecurityOrigin();

[dcheng, 2015/11/26 21:16:30]

In this case, the frame scheduler update has no security implications, but
someone browsing the code doesn't necessarily know that. A reader won't
understand why updateFrameSecurityOrigin() is called but
ScriptController::updateSecurityOrigin() is not.

As it turns out, ScriptContext's contract is that didUpdateSecurityOrigin() will
be called after a security origin change, so we should just stick to that
instead of adding an explicit call here.

 
     return true;
 }