[Android] Refactor Java Bridge tests

[Android] Refactor Java Bridge tests

This is to bring in some sanity, and to facilitate extracting common
test code to be used by both ContentShellTests and AwShellTests.

BUG=476880
Committed: https://crrev.com/af92aa448207e95fe7c4c0fd52e5d4e03d6f6d2c
Cr-Commit-Position: refs/heads/master@{#327294}

[mnaganov (inactive), 2015-04-23 11:40:59]

mnaganov@chromium.org changed reviewers:
+ torne@chromium.org

[mnaganov (inactive), 2015-04-24 11:58:23]

Ping!

[Torne, 2015-04-27 15:30:16]

lgtm

[mnaganov (inactive), 2015-04-27 20:29:03]

The CQ bit was checked by mnaganov@chromium.org

[commit-bot: I haz the power, 2015-04-27 20:29:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1102753002/1

[commit-bot: I haz the power, 2015-04-27 20:38:47]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-04-27 20:38:47]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[mnaganov (inactive), 2015-04-27 21:33:56]

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

[mnaganov (inactive), 2015-04-27 21:33:57]

tedchoc@: Hi Ted, can you please make an OWNER's review?

[Ted C, 2015-04-27 22:48:42]

lgtm

[mnaganov (inactive), 2015-04-28 15:54:59]

The CQ bit was checked by mnaganov@chromium.org

[commit-bot: I haz the power, 2015-04-28 15:55:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1102753002/1

[commit-bot: I haz the power, 2015-04-28 15:58:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-28 15:59:14]

Patchset 1 (id:??) landed as
https://crrev.com/af92aa448207e95fe7c4c0fd52e5d4e03d6f6d2c
Cr-Commit-Position: refs/heads/master@{#327294}