Only scroll on main if the targeted frames need to scroll on main

third_party/WebKit/Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 2043 matching lines @@
     ExceptionState& exceptionState) const {
   DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
     return String();
   }
 
   document->frame()->view()->updateAllLifecyclePhases();
 
-  Page* page = document->page();
-  if (!page)
-    return String();
-
-  return page->mainThreadScrollingReasonsAsText();
+  return document->frame()->view()->mainThreadScrollingReasonsAsText();
 }
 
 ClientRectList* Internals::nonFastScrollableRects(
     Document* document,
     ExceptionState& exceptionState) const {
   DCHECK(document);
   if (!document->frame()) {
     exceptionState.throwDOMException(InvalidAccessError,
                                      "The document provided is invalid.");
     return nullptr;
@@ skipping 1005 matching lines @@
 
 void Internals::crash() {
   CHECK(false) << "Intentional crash";
 }
 
 void Internals::setIsLowEndDevice(bool isLowEndDevice) {
   MemoryCoordinator::setIsLowEndDeviceForTesting(isLowEndDevice);
 }
 
 }  // namespace blink