cc: Make PaintCanvas abstract

cc/layers/painted_scrollbar_layer.cc

 // Copyright 2013 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/layers/painted_scrollbar_layer.h"
 
 #include <algorithm>
 
 #include "base/auto_reset.h"
 #include "cc/base/math_util.h"
 #include "cc/input/main_thread_scrolling_reason.h"
 #include "cc/layers/painted_scrollbar_layer_impl.h"
-#include "cc/paint/paint_canvas.h"
 #include "cc/paint/paint_flags.h"
+#include "cc/paint/skia_paint_canvas.h"
 #include "cc/resources/ui_resource_bitmap.h"
 #include "cc/trees/draw_property_utils.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkSize.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/skia_util.h"
@@ skipping 233 matching lines @@
 
 UIResourceBitmap PaintedScrollbarLayer::RasterizeScrollbarPart(
     const gfx::Rect& layer_rect,
     const gfx::Rect& content_rect,
     ScrollbarPart part) {
   DCHECK(!content_rect.size().IsEmpty());
   DCHECK(!layer_rect.size().IsEmpty());
 
   SkBitmap skbitmap;
   skbitmap.allocN32Pixels(content_rect.width(), content_rect.height());
-  PaintCanvas canvas(skbitmap);
+  SkiaPaintCanvas canvas(skbitmap);
 
   float scale_x =
       content_rect.width() / static_cast<float>(layer_rect.width());
   float scale_y =
       content_rect.height() / static_cast<float>(layer_rect.height());
 
   canvas.scale(SkFloatToScalar(scale_x), SkFloatToScalar(scale_y));
   canvas.translate(SkFloatToScalar(-layer_rect.x()),
                    SkFloatToScalar(-layer_rect.y()));
 
   SkRect layer_skrect = RectToSkRect(layer_rect);
   PaintFlags paint;
   paint.setAntiAlias(false);
   paint.setBlendMode(SkBlendMode::kClear);
   canvas.drawRect(layer_skrect, paint);
   canvas.clipRect(layer_skrect);
 
   scrollbar_->PaintPart(&canvas, part, layer_rect);
   // Make sure that the pixels are no longer mutable to unavoid unnecessary
   // allocation and copying.
   skbitmap.setImmutable();
 
   return UIResourceBitmap(skbitmap);
 }
 
 }  // namespace cc