virtual/override specifier cleanup in content/.

virtual/override specifier cleanup in content/.

These are changes detected by Chromecast not covered by the Linux build.

See: https://codereview.chromium.org/831863003

R=nasko@chromium.org
BUG=417463
Committed: https://crrev.com/5b7b77c964fbc852de546303428622029a0fd636
Cr-Commit-Position: refs/heads/master@{#309997}

[nasko, 2015-01-05 21:37:54]

nasko@chromium.org changed reviewers:
+ dcheng@chromium.org

[nasko, 2015-01-05 21:37:55]

Adding dcheng@ for visibility, as he's been doing this conversion for a while
now.

LGTM

[dcheng, 2015-01-05 21:40:51]

What GYP_DEFINES gate this code? I'm happy to adapt build/common.gypi to make
the rollout more gradual, to avoid these sort of breakages.

[gunsch, 2015-01-05 21:52:19]

On 2015/01/05 21:40:51, dcheng wrote:
> What GYP_DEFINES gate this code? I'm happy to adapt build/common.gypi to make
> the rollout more gradual, to avoid these sort of breakages.

Chromecast build is enabled entirely by "chromecast==1", so easily gated that
way (already declared in build/common.gypi). We have Chromecast builds on both
Android and Linux OS (for Android TV and the Chromecast dongle product,
respectively).

As far as virtual/override specifiers, I currently have CLs out to fix all the
virtual/override bits we depend on that hadn't yet been updated.

Unfortunately, we're behind in getting a trybot up and running, so I recognize
it's largely our fault that we don't have a good way to catch these at submit
time.

[gunsch, 2015-01-05 21:52:39]

The CQ bit was checked by gunsch@chromium.org

[commit-bot: I haz the power, 2015-01-05 21:54:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/794333003/1

[commit-bot: I haz the power, 2015-01-05 23:42:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-05 23:43:25]

Patchset 1 (id:??) landed as
https://crrev.com/5b7b77c964fbc852de546303428622029a0fd636
Cr-Commit-Position: refs/heads/master@{#309997}