Rename enums to fix GCC -Wchanges-meaning error Renamed enums Key and MouseButton to enum class KeyType and MouseButtonType to avoid name conflicts with union members in Event.h on GCC, and to follow the ANGLE style guide preference for scoped enums. BUG: angleproject:438226513 Change-Id: I8892b438b3b05a3ce4e14f8c0769b81722688da8 Signed-off-by: Sungyong Choi <sywow.choi@samsung.com> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6845484 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>