Warn on missing OVERRIDE/virtual everywhere, not just in header files.

Warn on missing OVERRIDE/virtual everywhere, not just in header files.

This is only enabled for Linux (so far).

BUG=115047
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=197788

[Ryan Sleevi, 2013-05-01 00:14:55]

Darin: Mind rubberstamping this global clean-up?

This just uses fixits for Linux build. The change was then cleaned up using
clang-format-diff, along with hand inspection at the end to work around
clang-format bugs (eg: handling of OVERRIDE)

The GYP change was previously reviewed, but has been impossible to land without
simultaneously landing the fixes, hence the hope to get this in while the tree
is quiet.

https://codereview.chromium.org/14696007/diff/1/build/common.gypi
File build/common.gypi (right):

https://codereview.chromium.org/14696007/diff/1/build/common.gypi#newcode1549
build/common.gypi:1549: }]
Previously reviewed on https://codereview.chromium.org/12261047/

[darin (slow to review), 2013-05-01 05:33:21]

LGTM

[commit-bot: I haz the power, 2013-05-01 19:53:54]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rsleevi@chromium.org/14696007/5001

[commit-bot: I haz the power, 2013-05-01 20:24:27]

Sorry for I got bad news for ya.
Compile failed with a clobber build on linux_clang.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_clan...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-05-01 23:26:31]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rsleevi@chromium.org/14696007/22001

[commit-bot: I haz the power, 2013-05-02 02:24:15]

Change committed as 197788