kStopIcon is a constant in the OSX APIs so rename kGenericStopIcon

Jumbo Mac fyi builder broke when a kStopIcon was introduced in
https://chromium-review.googlesource.com/c/chromium/src/+/1239010
because the OSX API has a kStopIcon in
.../MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/System/Library/Frameworks/Carbon.framework/Frameworks/HIToolbox.framework/Headers/Dialogs.h

This renames it to kGenericStopIcon to make the builds go again.

TBR=jrw@chromium.org,estade@chromium.org

Bug: 877702
Change-Id: Id6c675b539f8e3161ef322bf008174ec2911d4be
Reviewed-on: https://chromium-review.googlesource.com/c/1261042
Reviewed-by: Daniel Bratell <bratell@opera.com>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#596571}
3 files changed