Add Robolectric unittest suites to all.gyp and rename build targets.

Add Robolectric unittest suites to all.gyp and rename build targets.

Renaming chrome_shell_unit_tests to chrome_junit_tests as it tests code in the directory of the chrome_java target (and not the chrome_shell_java target). Same thing for content_shell_unit_tests. And adding chrome_junit_tests and content_junit_tests to the all.gyp file so we can run the tests on some of the bots.

BUG=

Committed: https://crrev.com/e240ab4e9c5841de8cb65226a80008600416c365
Cr-Commit-Position: refs/heads/master@{#322813}

[mikecase (-- gone --), 2015-03-27 16:32:56]

mikecase@chromium.org changed reviewers:
+ cjhopman@chromium.org

[cjhopman, 2015-03-29 02:09:51]

lgtm

[mikecase (-- gone --), 2015-03-30 16:04:48]

The CQ bit was checked by mikecase@chromium.org

[commit-bot: I haz the power, 2015-03-30 16:05:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1039733002/20001

[commit-bot: I haz the power, 2015-03-30 16:15:32]

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

[commit-bot: I haz the power, 2015-03-30 16:15:33]

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...)

[mikecase (-- gone --), 2015-03-30 16:30:35]

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

[Ted C, 2015-03-30 17:56:10]

lgtm

[mikecase (-- gone --), 2015-03-30 18:06:10]

The CQ bit was checked by mikecase@chromium.org

[commit-bot: I haz the power, 2015-03-30 18:06:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1039733002/20001

[commit-bot: I haz the power, 2015-03-30 18:14:54]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-30 18:15:24]

Patchset 2 (id:??) landed as
https://crrev.com/e240ab4e9c5841de8cb65226a80008600416c365
Cr-Commit-Position: refs/heads/master@{#322813}