Implement 'window.isSecureContext'.

third_party/WebKit/Source/core/frame/DOMWindow.cpp

Index: third_party/WebKit/Source/core/frame/DOMWindow.cpp
diff --git a/third_party/WebKit/Source/core/frame/DOMWindow.cpp b/third_party/WebKit/Source/core/frame/DOMWindow.cpp
index b514d469fe941be440f78783a670567f6b5e445a..3564707d547477f395a52709945f546c92f4b91c 100644
--- a/third_party/WebKit/Source/core/frame/DOMWindow.cpp
+++ b/third_party/WebKit/Source/core/frame/DOMWindow.cpp
@@ -8,6 +8,7 @@
 #include "bindings/core/v8/ScriptCallStackFactory.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/dom/ExecutionContext.h"
 #include "core/dom/SecurityContext.h"
 #include "core/events/MessageEvent.h"
 #include "core/frame/Frame.h"
@@ -155,6 +156,15 @@ void DOMWindow::resetLocation()
     }
 }
 
+bool DOMWindow::isSecureContext() const
+{
+    if (!frame() || !document())

[Srirama, 2015/09/28 14:42:07]

do we need the document check here? I think it is not required as it is
returning the reference and nowhere in this file there is a check for document.
Even if it is needed, atleast it should come before the frame check, as inside
frame we are using document.

[philipj_slow, 2015/09/28 15:20:26]

Right, RemoteDOMWindow::document() can return null but then we'll also have
passed an ASSERT_NOT_REACHED().

On the other hand, the only other plain document() call I can see first does an
isLocalDOMWindow() check, but to go that route it would be more reasonable,
IMHO, to just make this virtual.

+        return false;
+
+    String unusedErrorMessage;
+    return document()->isSecureContext(unusedErrorMessage, ExecutionContext::StandardSecureContextCheck);
+}
+
 void DOMWindow::postMessage(PassRefPtr<SerializedScriptValue> message, const MessagePortArray* ports, const String& targetOrigin, LocalDOMWindow* source, ExceptionState& exceptionState)
 {
     if (!isCurrentlyDisplayedInFrame())