Support setting just the Java Context for JUnit tests.

Support setting just the Java Context for JUnit tests.

JUnit/Robolectric tests run on the host without native code and so can't
set the application context the usual way. Provide a test-only method to
set only the Java-side context for this purpose.

Move the assertion about not changing the set context to
initApplicationContext because the JUnit tests will use a different
mock context for each test case.

BUG=552419
R=dgn@chromium.org

Committed: https://crrev.com/62e9dc641bd5e3967e59165e7e41f0a897ce9c0f
Cr-Commit-Position: refs/heads/master@{#361350}

[dgn, 2015-11-24 14:46:42]

On 2015/11/24 14:44:09, Torne wrote:

lgtm

[Torne, 2015-11-24 14:47:23]

The CQ bit was checked by torne@chromium.org

[Torne, 2015-11-24 14:47:28]

The CQ bit was checked by torne@chromium.org

[commit-bot: I haz the power, 2015-11-24 14:47:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1474723002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1474723002/1

[commit-bot: I haz the power, 2015-11-24 16:09:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-24 16:10:09]

Patchset 1 (id:??) landed as
https://crrev.com/62e9dc641bd5e3967e59165e7e41f0a897ce9c0f
Cr-Commit-Position: refs/heads/master@{#361350}