Implement the logic to kick off image decoding jobs for TileManager

cc/image.h

+// 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.
+
+#ifndef CC_IMAGE_H_
+#define CC_IMAGE_H_
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "cc/cc_export.h"
+#include "skia/ext/refptr.h"
+#include "third_party/skia/include/core/SkPixelRef.h"
+
+namespace cc {
+
+class CC_EXPORT Image : public base::RefCountedThreadSafe<Image> {

[reveman, 2012/12/05 19:48:46]

Does this need thread safe ref counting?

[qinmin, 2012/12/07 05:06:28]

Not necessarily, just to ensure when passing it to raster threads it won't get
deleted.  removed ref counting.
On 2012/12/05 19:48:46, David Reveman wrote:

+public:
+  static scoped_refptr<Image> Create(SkPixelRef* pixel_ref);

[reveman, 2012/12/05 19:48:46]

nit: maybe a blank line between static and normal function declarations.

[qinmin, 2012/12/07 05:06:28]

Done.

+  void Decode();

[Alpha Left Google, 2012/12/05 20:24:28]

Need some comments here.

Decode() is to populate the cache with the decoded image. It is not guaranteed
that the entry will stay there, since it can get evicted if there's too much
decode.

[qinmin, 2012/12/07 05:06:28]

Done.

+  bool PrepareToDecode();
+
+  SkPixelRef* pixel_ref() { return pixel_ref_.get(); }
+
+private:
+  explicit Image(const skia::RefPtr<SkPixelRef>&);
+  ~Image();
+
+  skia::RefPtr<SkPixelRef> pixel_ref_;
+
+  friend class base::RefCountedThreadSafe<Image>;
+  DISALLOW_COPY_AND_ASSIGN(Image);
+};
+
+}  // namespace cc
+
+#endif  // CC_IMAGE_H_