Add support for writing unit tests for Mojo-backed apps/extensions APIs.

extensions/test/extensions_unittests_main.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/base_paths.h"
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/path_service.h"
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
 #include "content/public/test/unittest_test_suite.h"
 #include "extensions/common/extension_paths.h"
 #include "extensions/test/test_extensions_client.h"
+#include "mojo/embedder/embedder.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace {
 
 class ExtensionsTestSuite : public base::TestSuite {
  public:
   ExtensionsTestSuite(int argc, char** argv);
 
  private:
   // base::TestSuite:
@@ skipping 25 matching lines @@
 void ExtensionsTestSuite::Shutdown() {
   ResourceBundle::CleanupSharedInstance();
   base::TestSuite::Shutdown();
 }
 
 }  // namespace
 
 int main(int argc, char** argv) {
   content::UnitTestTestSuite test_suite(new ExtensionsTestSuite(argc, argv));
 
+  mojo::embedder::Init();
   return base::LaunchUnitTests(argc,
                                argv,
                                base::Bind(&content::UnitTestTestSuite::Run,
                                           base::Unretained(&test_suite)));
 }