Change gtest launcher to run in parallel and retry failures by default.

Change gtest launcher, telemetry unittests to run in parallel and retry failures by default.

Previously, gtest-based tests would not run tests in parallel or retry failures
by default unless you specified the --test-launcher-bot-mode flag

This patch changes the behavior so that we run tests in parallel and retry failures by
default if we are running *all* of the tests (i.e.,  --gtest_filter was *not* specified).

You can still pass --test-launcher-jobs=X to control how many tests run in parallel,
and --test-launcher-retry-limit=0 to turn retries off and 
--test-launcher-retry-limit=X to control how many times to retry.

R=jam@chromium.org, phajdan.jr@chromium.org, ojan@chromium.org, tonyg@chromium.org
BUG=402089
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=289839

[Dirk Pranke, 2014-08-12 22:39:56]

I tested this manually (for both base_unittests and telemetry_unittests); adding
unit tests for this didn't seem useful.

I will take approval from you four as a proxy for inflicting this change on
chromium-dev@, unless any of you thinks I should check w/ the list first?

[eseidel, 2014-08-12 22:47:45]

Hot damn!  lgtm, but I expect you actually need someone else's lg.

[Dirk Pranke, 2014-08-12 22:52:08]

Double-checking, I realized that we wanted to run the tests in parallel by
default as well, so I've updated the patch for that.

[ojan, 2014-08-12 23:22:09]

lgtm

[jam, 2014-08-13 00:07:57]

lgtm

[Paweł Hajdan Jr., 2014-08-13 09:36:38]

I suggest to land the telemetry change in a separate patch.

https://codereview.chromium.org/469533002/diff/20001/base/test/launcher/test_...
File base/test/launcher/test_launcher.cc (right):

https://codereview.chromium.org/469533002/diff/20001/base/test/launcher/test_...
base/test/launcher/test_launcher.cc:397: // output. We also always redirect on
the bots to get the test output into
Please see this comment. It's important behavior: the bots MUST redirect stdio
even when running a single job. This is the only way we can get test output into
archived json summary.

[tonyg, 2014-08-13 14:25:43]

lgtm

[Dirk Pranke, 2014-08-13 16:56:04]

https://codereview.chromium.org/469533002/diff/20001/base/test/launcher/test_...
File base/test/launcher/test_launcher.cc (right):

https://codereview.chromium.org/469533002/diff/20001/base/test/launcher/test_...
base/test/launcher/test_launcher.cc:397: // output. We also always redirect on
the bots to get the test output into
On 2014/08/13 09:36:37, Paweł Hajdan Jr. wrote:
> Please see this comment. It's important behavior: the bots MUST redirect stdio
> even when running a single job. This is the only way we can get test output
into
> archived json summary.

Ah, okay. I will restore this and BotModeEnabled() then. Thanks!

[Dirk Pranke, 2014-08-13 20:58:51]

Updated w/ review feedback.

I left in the check for BotModeEnabled() for redirecting stdio, and split out
the telemetry change to a separate CL.

This patch is now much simpler :). Please take another look?

[jam, 2014-08-14 06:04:16]

slgtm, thanks

[jam, 2014-08-14 06:04:17]

slgtm, thanks

[Paweł Hajdan Jr., 2014-08-14 11:30:55]

LGTM

[Dirk Pranke, 2014-08-14 20:16:24]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-08-14 20:17:46]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dpranke@chromium.org/469533002/40001

[commit-bot: I haz the power, 2014-08-15 07:58:15]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_aosp on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_aosp/bu...)

[commit-bot: I haz the power, 2014-08-15 14:23:25]

Committed patchset #3 (40001) as 289839