linux_aura: Reenable parallel_jobs_.

In r239536 and r239680, I disabled all parallelization of unit test
jobs on linux_aura, because using the clipboard used a desktop wide
piece of X11 state, and running the tests in parallel meant that
tests which were using the clipboard would steal the clipboard from
other tests

The "actual" "problem" seems to have been "fixed." These tests appear
to be flakily failing in the same way in the GTK port, but are retried.
On lniux_aura, the test harness wasn't rerunning the tests and was just
marking them as failed. Now it's rerunning them, and they pass since
flaky tests are rerun one at a time.

This should still be a net win speed wise, since things fail flakily
about one in four times, and even that one flaky run still runs twice
as fast as the current runs.

BUG=239536
R=kbr@chromium.org, phajdan.jr@chromium.org

Review URL: https://codereview.chromium.org/125183005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243674 0039d316-1c4b-4281-b951-d872f2087c98

base/test/launcher/test_launcher.cc

@@ -331,17 +331,6 @@ TestLauncher::TestLauncher(TestLauncherDelegate* launcher_delegate,
     // --test-launcher-jobs flag.
     parallel_jobs_ = 1;
   }
-
-#if defined(USE_AURA) && defined(OS_LINUX) && !defined(OS_CHROMEOS)
-  // TODO(erg): Trying to parallelize tests on linux_aura makes things flaky
-  // because all shards share X11 state. http://crbug.com/326701
-  parallel_jobs_ = 1;
-
-  fprintf(stdout,
-          "Disabling parallelization due to the linux_aura flake. "
-          "http://crbug.com/326701\n");
-  fflush(stdout);
-#endif
 }
 
 TestLauncher::~TestLauncher() {