Make components_browsertests swarmable and add to main waterfall. (2nd try)

Make components_browsertests swarmable and add to main waterfall. (2nd try)

- Makes components_browsertests swarmable.
- Adds components_browsertests to the main waterfall for linux, mac and
  win bots.
- Updates the chromium tryserver to run components_browsertests as
  swarmable.
- Add content_shell as a dependency for components_browsertests for
  Mac, which is needed for the Content Shell helper on that platform.

The original CL did not add content_shell as a dependency for
components_browsertests, which made the build step for the isolate flaky
dependent upon whether content_shell happened to have already been built.

BUG=311270
Original CL:
Review: https://codereview.chromium.org/863023003/
Committed: https://crrev.com/7a3df3b7171fa87f556d22803fdc02a67e975865
Cr-Commit-Position: refs/heads/master@{#312886}

Revert CL:
https://codereview.chromium.org/856323003/
Committed: https://crrev.com/27ac8082963904942aaebcbf85620ae6e27ad5c9
Cr-Commit-Position: refs/heads/master@{#312976}

Committed: https://crrev.com/0c86f537ed20250297b0db7d00323143022a0ab5
Cr-Commit-Position: refs/heads/master@{#313163}

[nyquist, 2015-01-24 19:27:49]

nyquist@chromium.org changed reviewers:
+ jam@chromium.org

[nyquist, 2015-01-24 19:27:49]

jam: PTAL

Patch set 1 is a revert of your revert, and patch set 2 adds the necessary
dependency.

Reproed the issue locally by having a clean out-folder and only building
components_browsertests_run, and verified the fix in patch set 2 by re-gyping
and rebuilding components_browsertests_run and running the isolate which worked
(and does pop up the content shell window).

[jam, 2015-01-26 16:05:20]

lgtm

[nyquist, 2015-01-26 16:09:17]

The CQ bit was checked by nyquist@chromium.org

[commit-bot: I haz the power, 2015-01-26 16:09:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/874843002/20001

[commit-bot: I haz the power, 2015-01-26 16:10:02]

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

[commit-bot: I haz the power, 2015-01-26 16:10:02]

Try jobs failed on following builders:
  win_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu/builds/11...)
  win_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu_triggered...)

[nyquist, 2015-01-26 22:13:29]

The CQ bit was checked by nyquist@chromium.org

[commit-bot: I haz the power, 2015-01-26 22:13:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/874843002/40001

[commit-bot: I haz the power, 2015-01-26 23:12:49]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-01-26 23:14:04]

Patchset 3 (id:??) landed as
https://crrev.com/0c86f537ed20250297b0db7d00323143022a0ab5
Cr-Commit-Position: refs/heads/master@{#313163}