Turn the utility process image decoder into a Mojo service.

services/image_decoder/public/interfaces/image.mojom

+// Copyright 2015 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.
+
+// This file contains structures used to represent SkBitmaps in Mojo.
+
+// TODO(amistry): Consider moving somewhere else.

[Ken Rockot(use gerrit already), 2015/03/24 20:35:12]

What about somewhere like //skia/public{/interfaces/image.mojom,
type_converters.h}? It would be nice if these lived in the skia project, but
//skia might be a good compromise for now if OWNERS are OK with it.

Then this could just be module skia, which seems nicer.

[Anand Mistry (off Chromium), 2015/03/25 03:14:32]

Done.

+module services.image_decoder;
+
+// Mirror of SkColorType.
+enum ColorType {
+  UNKNOWN,
+  ALPHA_8,
+  RGB_565,
+  ARGB_4444,
+  RGBA_8888,
+  BGRA_8888,
+  INDEX_8,
+  GRAY_8,
+};
+
+// Mirror of SkAlphaType.
+enum AlphaType {
+  UNKNOWN,
+  OPAQUE,
+  PREMUL,
+  UNPREMUL,
+};
+
+// Mirror of SkColorProfileType.
+enum ColorProfileType {
+  LINEAR,
+  SRGB,
+};
+
+struct Image {
+  ColorType color_type;
+  AlphaType alpha_type;
+  ColorProfileType profile_type;
+
+  uint32 width;
+  uint32 height;
+
+  array<uint8> pixel_data;
+};