Prepare GuestView for removing swapped out RenderFrame.

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 f666c1c5dc73ac9c8f94896e491ca1a2088f378b..2a4fd3157bcd678ebdd00cfd01cbd983333ba6e3 100644
--- a/components/guest_view/renderer/guest_view_request.cc
+++ b/components/guest_view/renderer/guest_view_request.cc
@@ -9,6 +9,7 @@
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_view.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "third_party/WebKit/public/web/WebRemoteFrame.h"
 #include "third_party/WebKit/public/web/WebScopedMicrotaskSuppression.h"
 #include "third_party/WebKit/public/web/WebView.h"
 
@@ -88,7 +89,15 @@ void GuestViewAttachRequest::HandleResponse(const IPC::Message& message) {
 
   v8::HandleScope handle_scope(isolate());
   blink::WebFrame* frame = guest_proxy_render_view->GetWebView()->mainFrame();
-  v8::Local<v8::Value> window = frame->mainWorldScriptContext()->Global();
+  // TODO(lazyboy,nasko): The WebLocalFrame branch is not used when running
+  // on top of out-of-process iframes. Remove it once the code is converted.
+  v8::Local<v8::Value> window;
+  if (frame->isWebLocalFrame()) {
+    window = frame->mainWorldScriptContext()->Global();
+  } else {
+    window =
+        frame->toWebRemoteFrame()->deprecatedMainWorldScriptContext()->Global();
+  }
 
   const int argc = 1;
   scoped_ptr<v8::Local<v8::Value>[]> argv(new v8::Local<v8::Value>[argc]);