cc: Refactor content scale/bounds into draw properties

cc/scrollbar_layer.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.h"
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
 #include "cc/layer_painter.h"
 #include "cc/layer_tree_host.h"
@@ skipping 50 matching lines @@
     gfx::Size scaledBounds = computeContentBoundsForScale(scale, scale);
     if (scaledBounds.width() > maxTextureSize() || scaledBounds.height() > maxTextureSize()) {
          if (scaledBounds.width() > scaledBounds.height())
              return (maxTextureSize() - 1) / static_cast<float>(bounds().width());
          else
              return (maxTextureSize() - 1) / static_cast<float>(bounds().height());
    }
     return scale;
 }
 
-void ScrollbarLayer::setContentsScale(float contentsScale) {
-    contentsScale = clampScaleToMaxTextureSize(contentsScale);
-    ContentsScalingLayer::setContentsScale(contentsScale);
-    DCHECK_LE(contentBounds().width(), maxTextureSize());
-    DCHECK_LE(contentBounds().height(), maxTextureSize());
+void ScrollbarLayer::calculateContentsScale(
+  float idealContentsScale,
+  float* contentsScaleX,
+  float* contentsScaleY,
+  gfx::Size* contentBounds)
+{
+    ContentsScalingLayer::calculateContentsScale(
+        clampScaleToMaxTextureSize(idealContentsScale),
+        contentsScaleX,
+        contentsScaleY,
+        contentBounds);
+    DCHECK_LE(contentBounds->width(), maxTextureSize());
+    DCHECK_LE(contentBounds->height(), maxTextureSize());
 }
 
 void ScrollbarLayer::pushPropertiesTo(LayerImpl* layer)
 {
     ContentsScalingLayer::pushPropertiesTo(layer);
 
     ScrollbarLayerImpl* scrollbarLayer = static_cast<ScrollbarLayerImpl*>(layer);
 
     if (!scrollbarLayer->scrollbarGeometry())
         scrollbarLayer->setScrollbarGeometry(ScrollbarGeometryFixedThumb::create(make_scoped_ptr(m_geometry->clone())));
@@ skipping 218 matching lines @@
         updatePart(m_foreTrackUpdater.get(), m_foreTrack.get(), contentRect, queue, stats);
 
     // Consider the thumb to be at the origin when painting.
     WebKit::WebRect thumbRect = m_geometry->thumbRect(m_scrollbar.get());
     gfx::Rect originThumbRect = scrollbarLayerRectToContentRect(gfx::Rect(0, 0, thumbRect.width, thumbRect.height));
     if (!originThumbRect.IsEmpty())
         updatePart(m_thumbUpdater.get(), m_thumb.get(), originThumbRect, queue, stats);
 }
 
 }  // namespace cc