Make SecurityContext available in RemoteFrames.

public/web/WebFrame.h

Index: public/web/WebFrame.h
diff --git a/public/web/WebFrame.h b/public/web/WebFrame.h
index 902499906cabc9450a81c709bdfb11f3c51ad3d0..3064e8caae29301cb014db21323ab24e48bb49ee 100644
--- a/public/web/WebFrame.h
+++ b/public/web/WebFrame.h
@@ -155,6 +155,9 @@ public:
     virtual void setPermissionClient(WebPermissionClient*) = 0;
     virtual void setSharedWorkerRepositoryClient(WebSharedWorkerRepositoryClient*) = 0;
 
+    // The security origin of this frame.
+    virtual WebSecurityOrigin securityOrigin() const = 0;

[dcheng, 2014/11/18 23:31:40]

Do we need to call this on remote frames? If not, it might be better to start
with just making this available from WebLocalFrame.

[alexmos, 2014/11/19 00:33:04]

My RenderView test (see *.OriginReplicationForSwapOut in my other CL) needs
WebRemoteFrame::securityOrigin() to check that the replicated origin has been
set properly.

+
     // Geometry -----------------------------------------------------------
 
     // NOTE: These routines do not force page layout so their results may