Fix use_image_texture_target inconsistencies

cc/output/buffer_to_texture_target_map_unittest.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/output/buffer_to_texture_target_map.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/buffer_types.h"
+
+namespace cc {
+namespace {
+
+// Ensures that a map populated with various values can be serialized to/from
+// string successfully.
+TEST(BufferToTextureTargetMapTest, SerializeRoundTrip) {
+  BufferToTextureTargetMap test_map;
+  uint32_t next_value = 0;
+  for (int usage_idx = 0; usage_idx <= static_cast<int>(gfx::BufferUsage::LAST);
+       ++usage_idx) {
+    gfx::BufferUsage usage = static_cast<gfx::BufferUsage>(usage_idx);
+    for (int format_idx = 0;
+         format_idx <= static_cast<int>(gfx::BufferFormat::LAST);
+         ++format_idx) {
+      gfx::BufferFormat format = static_cast<gfx::BufferFormat>(format_idx);
+      test_map.insert(BufferToTextureTargetMap::value_type(
+          BufferToTextureTargetKey(usage, format), next_value++));
+    }
+  }
+
+  std::string serialized_map = BufferToTextureTargetMapToString(test_map);
+  BufferToTextureTargetMap deserialized_map =
+      StringToBufferToTextureTargetMap(serialized_map);
+  EXPECT_EQ(test_map, deserialized_map);
+}
+
+}  // namespace
+}  // namespace cc