Make scrollAnimatorEnabled work on Mac like it does on other platforms

ui/gfx/animation/animation.cc

 // 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.
 
 #include "ui/gfx/animation/animation.h"
 
 #include "build/build_config.h"
 #include "ui/gfx/animation/animation_container.h"
 #include "ui/gfx/animation/animation_delegate.h"
 #include "ui/gfx/animation/tween.h"
 #include "ui/gfx/geometry/rect.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #endif
 
+#if defined(OS_MACOSX)
+#include "base/mac/mac_util.h"
+#endif
+
 namespace gfx {
 
 Animation::Animation(base::TimeDelta timer_interval)
     : timer_interval_(timer_interval),
       is_animating_(false),
       delegate_(NULL) {
 }
 
 Animation::~Animation() {
   // Don't send out notification from the destructor. Chances are the delegate
@@ skipping 74 matching lines @@
     if (::SystemParametersInfo(SPI_GETCLIENTAREAANIMATION, 0, &result, 0)) {
       return !!result;
     }
   }
   return !::GetSystemMetrics(SM_REMOTESESSION);
 #else
   return true;
 #endif
 }
 
+// static
+bool Animation::ScrollAnimationsEnabledBySystem() {
+#if defined(OS_WIN)
+  return ShouldRenderRichAnimation();
+#elif defined(OS_MACOSX)
+  return base::mac::IsScrollAnimationEnabled();
+#else
+  return true;
+#endif
+}
+
 bool Animation::ShouldSendCanceledFromStop() {
   return false;
 }
 
 void Animation::SetStartTime(base::TimeTicks start_time) {
   start_time_ = start_time;
 }
 
 base::TimeDelta Animation::GetTimerInterval() const {
   return timer_interval_;
 }
 
 }  // namespace gfx