Introduce cc StructTraits unit tests

cc/test/run_all_unittests.cc

Index: cc/test/run_all_unittests.cc
diff --git a/cc/test/run_all_unittests.cc b/cc/test/run_all_unittests.cc
index 6d18d8d445b8120c9fdf6976efa97a1c7076927e..8aa3a1544ed16e7e79664852165dfa3fcabae6c0 100644
--- a/cc/test/run_all_unittests.cc
+++ b/cc/test/run_all_unittests.cc
@@ -4,11 +4,20 @@
 
 #include "base/bind.h"
 #include "base/test/launcher/unit_test_launcher.h"
+#include "base/test/test_io_thread.h"
 #include "cc/test/cc_test_suite.h"
+#include "mojo/edk/embedder/embedder.h"        // nogncheck

[Ken Rockot(use gerrit already), 2016/05/31 15:49:22]

Guess we need to fix this target somehow. This is annoying.

[Fady Samuel, 2016/05/31 15:57:20]

Looks like it's not actually necessary anymore. Removed.

+#include "mojo/edk/test/scoped_ipc_support.h"  // nogncheck
 
 int main(int argc, char** argv) {
   cc::CCTestSuite test_suite(argc, argv);
 
+  mojo::edk::Init();

[Ken Rockot(use gerrit already), 2016/05/31 15:49:22]

If you're not doing actual IPC (i.e. no multiprocess tests) you only need
mojo::edk::Init(). You can omit the IO thread and ScopedIPCSupport.

[Fady Samuel, 2016/05/31 15:57:20]

Done.

+  base::TestIOThread test_io_thread(base::TestIOThread::kAutoStart);
+  std::unique_ptr<mojo::edk::test::ScopedIPCSupport> ipc_support;
+  ipc_support.reset(
+      new mojo::edk::test::ScopedIPCSupport(test_io_thread.task_runner()));
+
   return base::LaunchUnitTests(
       argc,
       argv,