Switch RemoteWindowProxy to use v8::Context::NewRemoteContext.

components/guest_view/renderer/guest_view_request.cc

Index: components/guest_view/renderer/guest_view_request.cc
diff --git a/components/guest_view/renderer/guest_view_request.cc b/components/guest_view/renderer/guest_view_request.cc
index 1d26c3f4462bab8457123d1ec9e911feff15fd7f..abc7e3a72906814b54df0fbd183be45f877b85f8 100644
--- a/components/guest_view/renderer/guest_view_request.cc
+++ b/components/guest_view/renderer/guest_view_request.cc
@@ -97,8 +97,7 @@ void GuestViewAttachRequest::HandleResponse(const IPC::Message& message) {
   if (frame->isWebLocalFrame()) {
     window = frame->mainWorldScriptContext()->Global();
   } else {
-    window =
-        frame->toWebRemoteFrame()->deprecatedMainWorldScriptContext()->Global();
+    window = frame->toWebRemoteFrame()->globalProxy();
   }
 
   const int argc = 1;