ash: HiDPI user avatar for SessionController

ui/gfx/image/mojo/image_skia.mojom

+// 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.
+
+module gfx.mojom;
+
+// Mojo transport for ImageSkiaRep via shared buffer.
+struct ImageSkiaRep {
+  // Shared buffer handle to holds a serialized SkBitmap.
+  handle<shared_buffer> shared_buffer_handle;
+
+  // Byte size of the shared buffer.
+  uint64 buffer_byte_size;
+
+  // Corresponding scale of the bitmap.

[msw, 2017/03/23 20:47:53]

nit: "or 0 if unscaled"? Maybe explain what that means?

[xiyuan, 2017/03/24 05:45:31]

Done.

+  float scale;
+};
+
+// Mojo transport for existing representations of an ImageSkia via shared
+// buffer. Note it is caller's responsibility to ensure the ImageSkia contains
+// all needed representations.
+struct ImageSkia {
+  array<ImageSkiaRep> image_reps;
+};