content: implement unittests backend for Ozone GBM

base/test/launcher/unit_test_launcher.cc

Index: base/test/launcher/unit_test_launcher.cc
diff --git a/base/test/launcher/unit_test_launcher.cc b/base/test/launcher/unit_test_launcher.cc
index 9cd7d7127105ca900e33293f40ec0e9c86c7d9f9..b265f7e6e16c0b79a9c7b93fe9717ca6788095ed 100644
--- a/base/test/launcher/unit_test_launcher.cc
+++ b/base/test/launcher/unit_test_launcher.cc
@@ -191,6 +191,12 @@ int LaunchUnitTestsInternal(const RunTestSuiteCallback& run_test_suite,
     }
   }
 
+#if defined(USE_OZONE)
+  // It's prohibited multi-processes from taking card0. Only DRM master
+  // can take it. crbug.com/475633
+  force_single_process = true;

[spang, 2015/12/02 17:00:03]

I don't think this is worth losing parallelism over - we don't run base unit
tests with gbm in the typical case.

[dshwang, 2015/12/08 01:12:38]

I agree. do you have good idea?

My idea is 
- this class provide some hook or interface which client tests can add
additional command line.
- OzoneInitializerForTest or content_test_suite add additional command line via
the interface.

It will bloat the code.

[dshwang, 2015/12/08 22:19:33]

What I really want is that content_unittests and gl_unittests has
kSingleProcessTestsFlag command line on only ozone. Do you have good idea?

[dshwang, 2015/12/08 23:04:34]

Interesting. I assume that we will make test bots cover ozone-gbm. However, you
imply you don't have any plan.

Got it. Let's re-visit when we make test bots cover ozone-gbm.

+#endif
+
   if (CommandLine::ForCurrentProcess()->HasSwitch(kGTestHelpFlag) ||
       CommandLine::ForCurrentProcess()->HasSwitch(kGTestListTestsFlag) ||
       CommandLine::ForCurrentProcess()->HasSwitch(kSingleProcessTestsFlag) ||