Implement TransferableResource StructTraits

cc/resources/resource_format_utils.cc

+// Copyright 2016 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.
+
+#include "cc/resources/resource_format_utils.h"
+
+namespace cc {
+
+SkColorType ResourceFormatToClosestSkColorType(ResourceFormat format) {
+  // Use kN32_SkColorType if there is no corresponding SkColorType.
+  switch (format) {
+    case RGBA_4444:
+      return kARGB_4444_SkColorType;
+    case RGBA_8888:
+    case BGRA_8888:
+      return kN32_SkColorType;
+    case ALPHA_8:
+      return kAlpha_8_SkColorType;
+    case RGB_565:
+      return kRGB_565_SkColorType;
+    case LUMINANCE_8:
+      return kGray_8_SkColorType;
+    case ETC1:
+    case RED_8:
+    case LUMINANCE_F16:
+      return kN32_SkColorType;
+  }
+  NOTREACHED();
+  return kN32_SkColorType;
+}
+
+}  // namespace cc