Implement pinch-zoom scaling for main-frame scrollbars and pinch-zoom overlay scrollbars.

cc/animation.cc

 // Copyright 2012 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 "cc/animation.h"
 
 #include <cmath>
 
 #include "base/debug/trace_event.h"
 #include "base/string_util.h"
@@ skipping 41 matching lines @@
     , m_runState(WaitingForTargetAvailability)
     , m_iterations(1)
     , m_startTime(0)
     , m_alternatesDirection(false)
     , m_timeOffset(0)
     , m_needsSynchronizedStartTime(false)
     , m_suspended(false)
     , m_pauseTime(0)
     , m_totalPausedTime(0)
     , m_isControllingInstance(false)
+    , m_isImplAnimationOnly(false)
 {
 }
 
 Animation::~Animation()
 {
     if (m_runState == Running || m_runState == Paused)
         setRunState(Aborted, 0);
 }
 
 void Animation::setRunState(RunState runState, double monotonicTime)
@@ skipping 129 matching lines @@
 {
     // Currently, we only push changes due to pausing and resuming animations on the main thread.
     if (m_runState == Animation::Paused || other->m_runState == Animation::Paused) {
         other->m_runState = m_runState;
         other->m_pauseTime = m_pauseTime;
         other->m_totalPausedTime = m_totalPausedTime;
     }
 }
 
 }  // namespace cc