Separate VisualViewport layer tree creation from attachment.

third_party/WebKit/Source/core/loader/EmptyClients.cpp

 /*
  * Copyright (C) 2006 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. 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 97 matching lines @@
 
 void EmptyChromeClient::openTextDataListChooser(HTMLInputElement&) {}
 
 void EmptyChromeClient::openFileChooser(LocalFrame*, PassRefPtr<FileChooser>) {}
 
 void EmptyChromeClient::attachRootGraphicsLayer(GraphicsLayer* layer,
                                                 LocalFrame* localRoot) {
   Page* page = localRoot ? localRoot->page() : nullptr;
   if (!page)
     return;
-  page->frameHost().visualViewport().attachToLayerTree(layer);
+  page->frameHost().visualViewport().attachLayerTree(layer);
 }
 
 String EmptyChromeClient::acceptLanguages() {
   return String();
 }
 
 std::unique_ptr<WebFrameScheduler> EmptyChromeClient::createFrameScheduler(
     BlameContext*) {
   return WTF::makeUnique<EmptyFrameScheduler>();
 }
@@ skipping 63 matching lines @@
 
 std::unique_ptr<WebApplicationCacheHost>
 EmptyLocalFrameClient::createApplicationCacheHost(
     WebApplicationCacheHostClient*) {
   return nullptr;
 }
 
 EmptyRemoteFrameClient::EmptyRemoteFrameClient() = default;
 
 }  // namespace blink