Enable smooth scrolling on mac

content/renderer/render_view.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_RENDER_VIEW_H_
 #define CONTENT_RENDERER_RENDER_VIEW_H_
 #pragma once
 
 #include <deque>
 #include <map>
@@ skipping 653 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(ExternalPopupMenuTest, ShowPopupThenNavigate);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, DontIgnoreBackAfterNavEntryLimit);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, ImeComposition);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, InsertCharacters);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, JSBlockSentAfterPageLoad);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, LastCommittedUpdateState);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, OnHandleKeyboardEvent);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, OnImeStateChanged);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, OnNavStateChanged);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, OnSetTextDirection);
+  FRIEND_TEST_ALL_PREFIXES(RenderViewTest, OnUpdateWebPreferences);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, StaleNavigationsIgnored);
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, UpdateTargetURLWithInvalidURL);
 #if defined(OS_MACOSX)
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, MacTestCmdUp);
 #endif
   FRIEND_TEST_ALL_PREFIXES(RenderViewTest, SetHistoryLengthAndPrune);
 
   typedef std::map<GURL, double> HostZoomLevels;
 
   // Identifies an accessibility notification from webkit.
@@ skipping 561 matching lines @@
   // bunch of stuff, you should probably create a helper class and put your
   // data and methods on that to avoid bloating RenderView more.  You can use
   // the Observer interface to filter IPC messages and receive frame change
   // notifications.
   // ---------------------------------------------------------------------------
 
   DISALLOW_COPY_AND_ASSIGN(RenderView);
 };
 
 #endif  // CONTENT_RENDERER_RENDER_VIEW_H_