Revert of Back PaintRecord with PaintOpBuffer instead of SkPicture

cc/paint/paint_canvas.h

 // Copyright 2017 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.
 
 #ifndef CC_PAINT_PAINT_CANVAS_H_
 #define CC_PAINT_PAINT_CANVAS_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "build/build_config.h"
 #include "cc/paint/paint_export.h"
+#include "cc/paint/paint_record.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 
 namespace cc {
 
 class DisplayItemList;
 class PaintFlags;
-class PaintOpBuffer;
-
-using PaintRecord = PaintOpBuffer;
 
 class CC_PAINT_EXPORT PaintCanvas {
  public:
   virtual ~PaintCanvas() {}
 
   virtual SkMetaData& getMetaData() = 0;
-
-  // TODO(enne): this only appears to mostly be used to determine if this is
-  // recording or not, so could be simplified or removed.
   virtual SkImageInfo imageInfo() const = 0;
 
   // TODO(enne): It would be nice to get rid of flush() entirely, as it
   // doesn't really make sense for recording.  However, this gets used by
   // SkCanvasVideoRenderer which takes a PaintCanvas to paint both
   // software and hardware video.  This is super entangled with ImageBuffer
   // and canvas/video painting in Blink where the same paths are used for
   // both recording and gpu work.
   virtual void flush() = 0;
 
   virtual SkISize getBaseLayerSize() const = 0;
   virtual bool writePixels(const SkImageInfo& info,
                            const void* pixels,
                            size_t row_bytes,
                            int x,
                            int y) = 0;
   virtual int save() = 0;
   virtual int saveLayer(const SkRect* bounds, const PaintFlags* flags) = 0;
-  virtual int saveLayerAlpha(const SkRect* bounds, uint8_t alpha) = 0;
+  virtual int saveLayerAlpha(const SkRect* bounds, U8CPU alpha) = 0;
 
   virtual void restore() = 0;
   virtual int getSaveCount() const = 0;
   virtual void restoreToCount(int save_count) = 0;
   virtual void translate(SkScalar dx, SkScalar dy) = 0;
   virtual void scale(SkScalar sx, SkScalar sy) = 0;
   virtual void rotate(SkScalar degrees) = 0;
   virtual void concat(const SkMatrix& matrix) = 0;
   virtual void setMatrix(const SkMatrix& matrix) = 0;
 
@@ skipping 30 matching lines @@
   }
 
   virtual bool quickReject(const SkRect& rect) const = 0;
   virtual bool quickReject(const SkPath& path) const = 0;
   virtual SkRect getLocalClipBounds() const = 0;
   virtual bool getLocalClipBounds(SkRect* bounds) const = 0;
   virtual SkIRect getDeviceClipBounds() const = 0;
   virtual bool getDeviceClipBounds(SkIRect* bounds) const = 0;
   virtual void drawColor(SkColor color, SkBlendMode mode) = 0;
   void drawColor(SkColor color) { drawColor(color, SkBlendMode::kSrcOver); }
-
-  // TODO(enne): This is a synonym for drawColor with kSrc.  Remove it.
   virtual void clear(SkColor color) = 0;
 
   virtual void drawLine(SkScalar x0,
                         SkScalar y0,
                         SkScalar x1,
                         SkScalar y1,
                         const PaintFlags& flags) = 0;
   virtual void drawRect(const SkRect& rect, const PaintFlags& flags) = 0;
   virtual void drawIRect(const SkIRect& rect, const PaintFlags& flags) = 0;
   virtual void drawOval(const SkRect& oval, const PaintFlags& flags) = 0;
@@ skipping 129 matching lines @@
 // Following routines are used in print preview workflow to mark the
 // preview metafile.
 #if defined(OS_MACOSX)
 CC_PAINT_EXPORT void SetIsPreviewMetafile(PaintCanvas* canvas, bool is_preview);
 CC_PAINT_EXPORT bool IsPreviewMetafile(PaintCanvas* canvas);
 #endif
 
 }  // namespace cc
 
 #endif  // CC_PAINT_PAINT_CANVAS_H_