Activate LayerImpl tree with sync+push instead of pointer swap

cc/scrollbar_layer_impl.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/scrollbar_layer_impl.h"
 
 #include "cc/quad_sink.h"
 #include "cc/scrollbar_animation_controller.h"
 #include "cc/texture_draw_quad.h"
 #include "ui/gfx/rect_conversions.h"
@@ skipping 10 matching lines @@
 
 ScrollbarLayerImpl::ScrollbarLayerImpl(LayerTreeImpl* treeImpl, int id)
     : ScrollbarLayerImplBase(treeImpl, id)
     , m_scrollbar(this)
     , m_backTrackResourceId(0)
     , m_foreTrackResourceId(0)
     , m_thumbResourceId(0)
     , m_currentPos(0)
     , m_totalSize(0)
     , m_maximum(0)
+    , m_scrollLayerId(-1)
     , m_scrollbarOverlayStyle(WebScrollbar::ScrollbarOverlayStyleDefault)
     , m_orientation(WebScrollbar::Horizontal)
     , m_controlSize(WebScrollbar::RegularScrollbar)
     , m_pressedPart(WebScrollbar::NoPart)
     , m_hoveredPart(WebScrollbar::NoPart)
     , m_isScrollableAreaActive(false)
     , m_isScrollViewScrollbar(false)
     , m_enabled(false)
     , m_isCustomScrollbar(false)
     , m_isOverlayScrollbar(false)
 {
 }
 
 ScrollbarLayerImpl::~ScrollbarLayerImpl()
 {
 }
 
+ScrollbarLayerImpl* ScrollbarLayerImpl::toScrollbarLayer()
+{
+    return this;
+}
+
 void ScrollbarLayerImpl::setScrollbarGeometry(scoped_ptr<ScrollbarGeometryFixedThumb> geometry)
 {
     m_geometry = geometry.Pass();
 }
 
 void ScrollbarLayerImpl::setScrollbarData(WebScrollbar* scrollbar)
 {
     m_scrollbarOverlayStyle = scrollbar->scrollbarOverlayStyle();
     m_orientation = scrollbar->orientation();
     m_controlSize = scrollbar->controlSize();
@@ skipping 36 matching lines @@
 }
 
 gfx::Rect ScrollbarLayerImpl::scrollbarLayerRectToContentRect(const gfx::Rect& layerRect) const
 {
     // Don't intersect with the bounds as in layerRectToContentRect() because
     // layerRect here might be in coordinates of the containing layer.
     gfx::RectF contentRect = gfx::ScaleRect(layerRect, contentsScaleX(), contentsScaleY());
     return gfx::ToEnclosingRect(contentRect);
 }
 
+scoped_ptr<LayerImpl> ScrollbarLayerImpl::createLayerImpl(LayerTreeImpl* treeImpl)
+{
+    return ScrollbarLayerImpl::create(treeImpl, id()).PassAs<LayerImpl>();
+}
+
+void ScrollbarLayerImpl::pushPropertiesTo(LayerImpl* layer)
+{
+    LayerImpl::pushPropertiesTo(layer);
+
+    ScrollbarLayerImpl* scrollbarLayer = static_cast<ScrollbarLayerImpl*>(layer);
+
+    if (!scrollbarLayer->scrollbarGeometry())
+        scrollbarLayer->setScrollbarGeometry(ScrollbarGeometryFixedThumb::create(make_scoped_ptr(m_geometry->clone())));
+
+    scrollbarLayer->setScrollbarData(&m_scrollbar);
+
+    scrollbarLayer->setBackTrackResourceId(m_backTrackResourceId);
+    scrollbarLayer->setForeTrackResourceId(m_foreTrackResourceId);
+    scrollbarLayer->setThumbResourceId(m_thumbResourceId);
+}
+
 void ScrollbarLayerImpl::appendQuads(QuadSink& quadSink, AppendQuadsData& appendQuadsData)
 {
     bool premultipledAlpha = false;
     bool flipped = false;
     gfx::PointF uvTopLeft(0.f, 0.f);
     gfx::PointF uvBottomRight(1.f, 1.f);
     gfx::Rect boundsRect(gfx::Point(), bounds());
     gfx::Rect contentBoundsRect(gfx::Point(), contentBounds());
 
     SharedQuadState* sharedQuadState = quadSink.useSharedQuadState(createSharedQuadState());
@@ skipping 125 matching lines @@
 {
     return m_owner->m_isCustomScrollbar;
 }
 
 const char* ScrollbarLayerImpl::layerTypeAsString() const
 {
     return "ScrollbarLayer";
 }
 
 }  // namespace cc