cc: Update discardable image metadata generation to get PaintImages.

cc/paint/paint_op_buffer.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_OP_BUFFER_H_
 #define CC_PAINT_PAINT_OP_BUFFER_H_
 
 #include <stdint.h>
 
 #include "base/logging.h"
 #include "base/memory/aligned_memory.h"
 #include "cc/base/math_util.h"
 #include "cc/paint/paint_canvas.h"
 #include "cc/paint/paint_export.h"
 #include "cc/paint/paint_flags.h"
 #include "third_party/skia/include/core/SkPicture.h"
 #include "third_party/skia/include/core/SkRect.h"
 #include "third_party/skia/include/core/SkTextBlob.h"
 
 // PaintOpBuffer is a reimplementation of SkLiteDL.
 // See: third_party/skia/src/core/SkLiteDL.h.
 
 namespace cc {
-
 class DisplayItemList;
 
 class CC_PAINT_EXPORT ThreadsafeMatrix : public SkMatrix {
  public:
   explicit ThreadsafeMatrix(const SkMatrix& matrix) : SkMatrix(matrix) {
     (void)getType();
   }
 };
 
 class CC_PAINT_EXPORT ThreadsafePath : public SkPath {
@@ skipping 934 matching lines @@
   size_t subrecord_bytes_used_ = 0;
   bool has_discardable_images_ = false;
   SkRect cull_rect_;
 
   DISALLOW_COPY_AND_ASSIGN(PaintOpBuffer);
 };
 
 }  // namespace cc
 
 #endif  // CC_PAINT_PAINT_OP_BUFFER_H_