[iOS] Load chrome_300_percent.pak file on @3x devices.

[iOS] Load chrome_300_percent.pak file on @3x devices.

This CL adds support for loading assets from the chrome_300_percent.pak
file on devices that support @3x scale.

BUG=423762
Committed: https://crrev.com/f1f77bfa7af91abcab9b7f69f9d5c3d65d4c08e8
Cr-Commit-Position: refs/heads/master@{#301142}

[lliabraa, 2014-10-15 19:38:03]

lliabraa@chromium.org changed reviewers:
+ rohitrao@chromium.org

[lliabraa, 2014-10-17 12:20:14]

lliabraa@chromium.org changed reviewers:
+ tony@chromium.org

[lliabraa, 2014-10-17 12:20:15]

+tony for OWNERS

[tony, 2014-10-17 16:54:24]

LGTM

[rohitrao (ping after 24h), 2014-10-21 20:31:21]

Do you think we should put this behind a flag?  Or would we just revert this CL
if we wanted to back this out?

[lliabraa, 2014-10-21 20:37:08]

On 2014/10/21 20:31:21, rohitrao wrote:
> Do you think we should put this behind a flag?  Or would we just revert this
CL
> if we wanted to back this out?

We can just revert this CL and we won't have any references to the 300 percent
pak file at runtime.

[rohitrao (ping after 24h), 2014-10-21 20:38:10]

lgtm

[lliabraa, 2014-10-24 16:58:23]

The CQ bit was checked by lliabraa@chromium.org

[commit-bot: I haz the power, 2014-10-24 16:59:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/646773004/1

[commit-bot: I haz the power, 2014-10-24 17:53:40]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-24 17:54:19]

Patchset 1 (id:??) landed as
https://crrev.com/f1f77bfa7af91abcab9b7f69f9d5c3d65d4c08e8
Cr-Commit-Position: refs/heads/master@{#301142}