A speculative Revert for r165872 - Remove static thread pointers from CC, attempt 2

cc/layer_impl.cc

 // Copyright 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 "config.h"
 
 #include "cc/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/stringprintf.h"
@@ skipping 47 matching lines @@
     , m_debugBorderColor(0)
     , m_debugBorderWidth(0)
     , m_filter(0)
     , m_drawTransformIsAnimating(false)
     , m_screenSpaceTransformIsAnimating(false)
 #ifndef NDEBUG
     , m_betweenWillDrawAndDidDraw(false)
 #endif
     , m_layerAnimationController(LayerAnimationController::create(this))
 {
+    DCHECK(Proxy::isImplThread());
     DCHECK(m_layerId > 0);
 }
 
 LayerImpl::~LayerImpl()
 {
+    DCHECK(Proxy::isImplThread());
 #ifndef NDEBUG
     DCHECK(!m_betweenWillDrawAndDidDraw);
 #endif
     SkSafeUnref(m_filter);
 }
 
 void LayerImpl::addChild(scoped_ptr<LayerImpl> child)
 {
     child->setParent(this);
     m_children.append(child.Pass());
@@ skipping 614 matching lines @@
 
 void LayerImpl::setVerticalScrollbarLayer(ScrollbarLayerImpl* scrollbarLayer)
 {
     if (!m_scrollbarAnimationController)
         m_scrollbarAnimationController = ScrollbarAnimationController::create(this);
     m_scrollbarAnimationController->setVerticalScrollbarLayer(scrollbarLayer);
     m_scrollbarAnimationController->updateScrollOffset(this);
 }
 
 }