There is a macro to compare two enum values to see that they have the same numerical value called STATIC_ASSERT_ENUM. It is so popular that it exists 12 different places. Preferably everyone should use the one in third_party/WebKit/Source/platform/wtf/Assertions.h but reasons.

bratell@bratell-linux:~/src/chromium/src$ git grep "#define STATIC_ASSERT_ENUM"
components/printing/renderer/print_web_view_helper.cc:#define STATIC_ASSERT_ENUM(a, b)                            \
content/browser/web_contents/web_contents_view_mac.mm:#define STATIC_ASSERT_ENUM(a, b)                            \
content/child/assert_matching_enums.cc:#define STATIC_ASSERT_ENUM(a, b)                            \
content/child/web_url_request_util.cc:#define STATIC_ASSERT_ENUM(a, b)                            \
content/public/common/web_preferences.cc:#define STATIC_ASSERT_ENUM(a, b)                            \
content/renderer/pepper/pepper_plugin_instance_impl.cc:#define STATIC_ASSERT_ENUM(a, b)                            \
media/blink/webmediaplayer_impl.cc:#define STATIC_ASSERT_ENUM(a, b)                            \
media/gpu/gpu_video_accelerator_util.cc:#define STATIC_ASSERT_ENUM_MATCH(name)                             \
pdf/pdfium/pdfium_assert_matching_enums.cc:#define STATIC_ASSERT_ENUM(a, b)                            \
ppapi/thunk/ppb_text_input_thunk.cc:#define STATIC_ASSERT_ENUM(a, b)                            \
third_party/WebKit/Source/platform/wtf/Assertions.h:#define STATIC_ASSERT_ENUM(a, b)                            \
third_party/WebKit/public/web/ConsoleMessageStructTraits.cpp:#define STATIC_ASSERT_ENUM(a, b)                            \

I noticed it while doing jumbo but this is really just a generic code issue. Adding people that I know care about the code to CC.