Fix use_image_texture_target inconsistencies

cc/output/buffer_to_texture_target_map.h

+// 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.
+
+#ifndef CC_OUTPUT_BUFFER_TO_TEXTURE_TARGET_MAP_H_
+#define CC_OUTPUT_BUFFER_TO_TEXTURE_TARGET_MAP_H_
+
+#include <map>
+#include <string>
+
+#include "cc/base/cc_export.h"
+#include "ui/gfx/buffer_types.h"
+
+namespace cc {
+// A map of GPU Memory Buffer usage/format to GL texture target.
+using BufferToTextureTargetKey = std::pair<gfx::BufferUsage, gfx::BufferFormat>;
+using BufferToTextureTargetMap = std::map<BufferToTextureTargetKey, uint32_t>;
+
+// Converts a serialized ImageTextureTargetsMap back to the runtime format.
+// Serialization takes the form:
+//   "usage,format,target;usage,format,target;...;usage,format,target"
+CC_EXPORT BufferToTextureTargetMap
+StringToBufferToTextureTargetMap(const std::string& str);
+
+// Converts an ImageTextureTargetsMap to a string representation of the format:
+//   "usage,format,target;usage,format,target;...;usage,format,target"
+CC_EXPORT std::string BufferToTextureTargetMapToString(
+    const BufferToTextureTargetMap& map);
+
+// Returns a default-initialized BufferToTextureTargetsMap where every entry
+// maps to GL_TEXTURE_2D.
+CC_EXPORT BufferToTextureTargetMap DefaultBufferToTextureTargetMapForTesting();
+
+}  // namespace cc
+
+#endif  // CC_OUTPUT_BUFFER_TO_TEXTURE_TARGET_MAP_H_