Introducing gpu::CommandBufferId as a distinct, IdType<...>-based type.

base/BUILD.gn

 # Copyright (c) 2013 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 324 matching lines @@
     "files/scoped_temp_dir.h",
     "format_macros.h",
     "gtest_prod_util.h",
     "guid.cc",
     "guid.h",
     "guid_posix.cc",
     "guid_win.cc",
     "hash.cc",
     "hash.h",
     "id_map.h",
+    "id_type.h",
     "ios/crb_protocol_observers.h",
     "ios/crb_protocol_observers.mm",
     "ios/device_util.h",
     "ios/device_util.mm",
     "ios/ios_util.h",
     "ios/ios_util.mm",
     "ios/ns_error_util.h",
     "ios/ns_error_util.mm",
     "ios/scoped_critical_action.h",
     "ios/scoped_critical_action.mm",
@@ skipping 1230 matching lines @@
     "i18n/file_util_icu_unittest.cc",
     "i18n/icu_string_conversions_unittest.cc",
     "i18n/message_formatter_unittest.cc",
     "i18n/number_formatting_unittest.cc",
     "i18n/rtl_unittest.cc",
     "i18n/streaming_utf8_validator_unittest.cc",
     "i18n/string_search_unittest.cc",
     "i18n/time_formatting_unittest.cc",
     "i18n/timezone_unittest.cc",
     "id_map_unittest.cc",
+    "id_type_unittest.cc",
     "ios/device_util_unittest.mm",
     "ios/weak_nsobject_unittest.mm",
     "json/json_parser_unittest.cc",
     "json/json_reader_unittest.cc",
     "json/json_value_converter_unittest.cc",
     "json/json_value_serializer_unittest.cc",
     "json/json_writer_unittest.cc",
     "json/string_escape_unittest.cc",
     "lazy_instance_unittest.cc",
     "logging_unittest.cc",
@@ skipping 448 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }