Fix HotwordServiceTest under ubsan: no more vcalls on garbage.

chrome/browser/extensions/component_loader_unittest.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/component_loader.h"
 
 #include <stddef.h>
 
 #include <string>
 
@@ skipping 228 matching lines @@
   component_loader_.AddDefaultComponentExtensions(false);
   component_loader_.LoadAll();
   unsigned int default_count = registry->enabled_extensions().size();
 
   // Clear the list of loaded extensions, and reload with one more.
   extension_service_.clear_extensions();
   component_loader_.Add(manifest_contents_, extension_path_);
   component_loader_.LoadAll();
 
   EXPECT_EQ(default_count + 1, registry->enabled_extensions().size());
+
+  base::MessageLoop::current()->RunUntilIdle();
 }
 
 TEST_F(ComponentLoaderTest, AddOrReplace) {
   EXPECT_EQ(0u, component_loader_.registered_extensions_count());
   component_loader_.AddDefaultComponentExtensions(false);
   size_t const default_count = component_loader_.registered_extensions_count();
   base::FilePath known_extension = GetBasePath()
       .AppendASCII("override_component_extension");
   base::FilePath unknow_extension = extension_path_;
   base::FilePath invalid_extension = GetBasePath()
@@ skipping 17 matching lines @@
   EXPECT_EQ(0u, extension_service_.unloaded_count());
 
   // replace loaded component extension.
   component_loader_.AddOrReplace(known_extension);
   EXPECT_EQ(default_count + 1, registry->enabled_extensions().size());
   EXPECT_EQ(1u, extension_service_.unloaded_count());
 
   // Add an invalid component extension.
   std::string extension_id = component_loader_.AddOrReplace(invalid_extension);
   EXPECT_TRUE(extension_id.empty());
+  base::MessageLoop::current()->RunUntilIdle();
 }
 
 }  // namespace extensions