Initialize command line arguments for Mojo apptests.

mojo/application/application_test_main_chromium.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/test/test_timeouts.h"
+#include "mojo/application/application_runner_chromium.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_test_base.h"
 
 MojoResult MojoMain(MojoHandle handle) {
   // An AtExitManager instance is needed to construct message loops.
   base::AtExitManager at_exit;
 
-  // Initialize test timeouts, which requires CommandLine::ForCurrentProcess().
-  // TODO(msw): Plumb relevant command line args before initializing timeouts.
-  base::CommandLine::Init(0, nullptr);
+  // Initialize test timeouts, which requires an initialized CommandLine.
+  mojo::ApplicationRunnerChromium::InitBaseCommandLine();
   TestTimeouts::Initialize();
 
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  int argc = 0;
+  const char** argv = new const char* [command_line->argv().size()];
+  for (auto& arg : command_line->argv())
+    argv[argc++] = arg.c_str();
+  // TODO(msw): Avoid calling InitGoogleTest again in mojo::test::RunAllTests.
+  testing::InitGoogleTest(&argc, const_cast<char**>(&(argv[0])));
+
   return mojo::test::RunAllTests(handle);
 }