Fix ChromiumLinkerTest crashing due to null Context

Fix ChromiumLinkerTest crashing due to null Context

This patch fixes an exception thrown while running ChromiumLinkerTest
which was caused by null Context. The solution is to make
ChromeLinkerTestApplication be a subclass of BaseChromiumApplication
because it automatically calls ApplicationStatus.initialize() in
onCreate().

BUG=459669
Committed: https://crrev.com/0e657f72853e60d37eb4d1fab5be0fa674028d6b
Cr-Commit-Position: refs/heads/master@{#317358}

[petrcermak, 2015-02-20 12:11:24]

petrcermak@chromium.org changed reviewers:
+ tedchoc@chromium.org

[petrcermak, 2015-02-20 12:11:24]

Hi, please review this small patch.

Thanks,
Petr

[rmcilroy, 2015-02-20 13:34:40]

On 2015/02/20 12:11:24, petrcermak wrote:
> Hi, please review this small patch.
> 
> Thanks,
> Petr

lgtm (but I think you still need Ted's OWNER stamp).

[Ted C, 2015-02-20 17:40:08]

lgtm

[petrcermak, 2015-02-20 17:40:30]

The CQ bit was checked by petrcermak@chromium.org

[commit-bot: I haz the power, 2015-02-20 17:41:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/941953003/1

[commit-bot: I haz the power, 2015-02-20 18:40:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-20 18:41:06]

Patchset 1 (id:??) landed as
https://crrev.com/0e657f72853e60d37eb4d1fab5be0fa674028d6b
Cr-Commit-Position: refs/heads/master@{#317358}