Add Mojo application test support to Chromium.

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/logging.h"
+#include "base/message_loop/message_loop.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_impl.h"
 #include "mojo/public/cpp/application/application_test_base.h"
-#include "mojo/public/cpp/environment/logging.h"
+#include "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 
 MojoResult MojoMain(MojoHandle shell_handle) {
-  // An Environment instance is needed to construct run loops.
-  mojo::Environment environment;
+  // An AtExitManager instance is needed to construct message loops.
+  base::AtExitManager at_exit;

[jamesr, 2014/11/11 23:07:33]

this is only needed if we're creating a base::MessageLoop, right? do we know at
compile time that mojo::Environment::Instantiate..() is going to make a
base::MessageLoop here always in that case?

[msw, 2014/11/11 23:18:28]

Yes, this file (application_test_main_chromium.cc) uses the chromium-environment
and will use base::MessageLoop.

I previously suggested defining mojo::Environment ctors in the
chromium-environment to handle creation of the AtExitManager, so this bit would
be abstracted away like the run loop helpers using base::MessageLoop or
mojo::RunLoop, but Trung really didn't like that idea.

So again, perhaps these files and ApplicationTestBase should be split up so we
can be explicit about the environment everywhere?

[jamesr, 2014/11/11 23:22:21]

OK... then at line 21 why don't you just call base::MessageLoop directly?  Why
call through mojo::Environment?  This file already depends on base.
Maybe I'm think but it seems like they already are separate files so they can
use different code.

[msw, 2014/11/11 23:29:33]

For consistency with ApplicationTestBase and the standalone main.cc.
(I didn't have any other really compelling reasons)
Yeah, both MojoMain()s can use loops directly, ApplicationTestBase can't right
now; it seems like they should be consistent.

 
   {
     // This RunLoop is used for init, and then destroyed before running tests.
     mojo::Environment::InstantiateDefaultRunLoop();
 
     // Construct an ApplicationImpl just for the GTEST commandline arguments.
     // GTEST command line arguments are supported amid application arguments:
     // $ mojo_shell 'mojo:example_apptests arg1 --gtest_filter=foo arg2'
     mojo::ApplicationDelegate dummy_application_delegate;
     mojo::ApplicationImpl app(&dummy_application_delegate, shell_handle);
-    MOJO_CHECK(app.WaitForInitialize());
+    CHECK(app.WaitForInitialize());
 
     // InitGoogleTest expects (argc + 1) elements, including a terminating NULL.
     // It also removes GTEST arguments from |argv| and updates the |argc| count.
     // TODO(msw): Provide tests access to these actual command line arguments.
     const std::vector<std::string>& args = app.args();
-    MOJO_CHECK(args.size() <
-               static_cast<size_t>(std::numeric_limits<int>::max()));
+    CHECK_LT(args.size(), static_cast<size_t>(std::numeric_limits<int>::max()));
     int argc = static_cast<int>(args.size());
     std::vector<const char*> argv(argc + 1);
     for (int i = 0; i < argc; ++i)
       argv[i] = args[i].c_str();
     argv[argc] = nullptr;
 
     testing::InitGoogleTest(&argc, const_cast<char**>(&(argv[0])));
     mojo::test::SetShellHandle(app.UnbindShell());
     mojo::Environment::DestroyDefaultRunLoop();
   }
 
   int result = RUN_ALL_TESTS();
 
   shell_handle = mojo::test::PassShellHandle().release().value();
   MojoResult close_result = MojoClose(shell_handle);
-  MOJO_CHECK(close_result == MOJO_RESULT_OK);
+  CHECK_EQ(close_result, MOJO_RESULT_OK);
 
   return (result == 0) ? MOJO_RESULT_OK : MOJO_RESULT_UNKNOWN;
 }