Add ExtensionsTestBrowserContext class for test.

extensions/browser/extensions_test_browser_context.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 "extensions/browser/extensions_test_browser_context.h"
+
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "extensions/browser/extensions_browser_client.h"
+#include "extensions/browser/test_extensions_browser_client.h"
+
+namespace extensions {
+
+ExtensionsTestBrowserContext::ExtensionsTestBrowserContext() :
+  extensions_browser_client_(this) {
+  BrowserContextDependencyManager::GetInstance()
+      ->CreateBrowserContextServicesForTest(this);

[James Cook, 2014/07/21 20:42:47]

I don't think you can do this. If an earlier unit test registered browser
context service factories this will attempt to create the services. If the
services depend on a Profile and not a BrowserContext things will crash (usually
in valgrind bots).  I had this problem with
https://codereview.chromium.org/381283002

We need a better solution to this problem. I'm not sure yet what it is. I think
only running extensions unittests in the extensions_unittest binary would help.

+  ExtensionsBrowserClient::Set(&extensions_browser_client_);
+}
+
+ExtensionsTestBrowserContext::~ExtensionsTestBrowserContext() {
+  BrowserContextDependencyManager::GetInstance()
+      ->DestroyBrowserContextServices(this);
+  ExtensionsBrowserClient::Set(NULL);
+}
+
+}  // namespace extensions