Corrected reused include guards

If the same include guard is used twice, it becomes impossible
to include both those headers in the same translation unit and
that can be hard to debug and understand. This patch renames
some include guards that have the same names (copy/paste) as
existing include guards.

Found while working on a PRESUBMIT test for include guards. It will
not warn for these things, but it was easy to add that test locally.

There are another few thousand files that have wrongly named
include guards. Left as an exercise to the reader.

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: Ic7ba08558d3fbae0d3bee843f3092d472f8c643b
Reviewed-on: https://chromium-review.googlesource.com/937712
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#539800}
12 files changed