cc: Update discardable image metadata generation to get PaintImages.

cc/paint/discardable_image_store.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_DISCARDABLE_IMAGE_STORE_H_
+#define CC_PAINT_DISCARDABLE_IMAGE_STORE_H_
+
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkMatrix.h"
+#include "third_party/skia/include/core/SkRect.h"
+
+namespace cc {
+class PaintFlags;
+class PaintImage;
+
+class DiscardableImageStore {

[vmpstr, 2017/04/27 16:28:54]

Why don't we just make this a concrete class?

[Khushal, 2017/04/27 22:06:02]

Done.

+ public:
+  virtual ~DiscardableImageStore() {}
+
+  virtual void AddImage(const PaintImage& paint_image,
+                const SkRect& src,
+                const SkRect& rect,
+                const SkMatrix* local_matrix,
+                const PaintFlags& flags) = 0;
+
+  // This canvas is used only for tracking transform/clip/filter state from the
+  // non-drawing ops.
+  virtual SkCanvas* NoDrawCanvas() = 0;
+};
+
+}  // namespace cc
+
+#endif  // CC_PAINT_DISCARDABLE_IMAGE_STORE_H_