Update WebLocalFrameImpl and RotationViewportAnchor for root layer scrolling.

Source/web/WebLocalFrameImpl.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 651 matching lines @@
 void WebLocalFrameImpl::setContentSettingsClient(WebContentSettingsClient* contentSettingsClient)
 {
     m_contentSettingsClient = contentSettingsClient;
 }
 
 void WebLocalFrameImpl::setSharedWorkerRepositoryClient(WebSharedWorkerRepositoryClient* client)
 {
     m_sharedWorkerRepositoryClient = SharedWorkerRepositoryClientImpl::create(client);
 }
 
+ScrollableArea* WebLocalFrameImpl::layoutViewportScrollableArea() const
+{
+    if (FrameView* view = frameView())
+        return view->layoutViewportScrollableArea();
+    return nullptr;
+}
+
 WebSize WebLocalFrameImpl::scrollOffset() const
 {
-    FrameView* view = frameView();
-    if (!view)
-        return WebSize();
-    return view->scrollOffset();
+    if (ScrollableArea* scrollableArea = layoutViewportScrollableArea())
+        return toIntSize(scrollableArea->scrollPosition());
+    return WebSize();
 }
 
 WebSize WebLocalFrameImpl::minimumScrollOffset() const
 {
-    FrameView* view = frameView();
-    if (!view)
-        return WebSize();
-    return toIntSize(view->minimumScrollPosition());
+    if (ScrollableArea* scrollableArea = layoutViewportScrollableArea())
+        return toIntSize(scrollableArea->minimumScrollPosition());
+    return WebSize();
 }
 
 WebSize WebLocalFrameImpl::maximumScrollOffset() const
 {
-    FrameView* view = frameView();
-    if (!view)
-        return WebSize();
-    return toIntSize(view->maximumScrollPosition());
+    if (ScrollableArea* scrollableArea = layoutViewportScrollableArea())
+        return toIntSize(scrollableArea->maximumScrollPosition());
+    return WebSize();
 }
 
 void WebLocalFrameImpl::setScrollOffset(const WebSize& offset)
 {
-    if (FrameView* view = frameView())
-        view->setScrollPosition(IntPoint(offset.width, offset.height), ProgrammaticScroll);
+    if (ScrollableArea* scrollableArea = layoutViewportScrollableArea())
+        scrollableArea->setScrollPosition(IntPoint(offset.width, offset.height), ProgrammaticScroll);
 }
 
 WebSize WebLocalFrameImpl::contentsSize() const
 {
     if (FrameView* view = frameView())
         return view->contentsSize();
     return WebSize();
 }
 
 bool WebLocalFrameImpl::hasVisibleContent() const
@@ skipping 1474 matching lines @@
 }
 
 WebSandboxFlags WebLocalFrameImpl::effectiveSandboxFlags() const
 {
     if (!frame())
         return WebSandboxFlags::None;
     return static_cast<WebSandboxFlags>(frame()->loader().effectiveSandboxFlags());
 }
 
 } // namespace blink