Split testing_pref_service.h/.cc into two parts, generic vs. Chrome-specific.

chrome/browser/extensions/external_policy_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 <set>
 #include <string>
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/values.h"
 #include "base/version.h"
 #include "chrome/browser/extensions/external_policy_loader.h"
 #include "chrome/browser/extensions/external_provider_impl.h"
 #include "chrome/browser/extensions/external_provider_interface.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/manifest.h"
 #include "chrome/common/pref_names.h"
-#include "chrome/test/base/testing_pref_service.h"
+#include "chrome/test/base/testing_pref_service_syncable.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/test/test_browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::BrowserThread;
 
 namespace extensions {
 
 class ExternalPolicyLoaderTest : public testing::Test {
  public:
@@ skipping 111 matching lines @@
   // Add invalid entries.
   forced_extensions.SetString("invalid", "http://www.example.com/crx");
   forced_extensions.SetString("dddddddddddddddddddddddddddddddd", "");
   forced_extensions.SetString("invalid", "bad");
 
   MockExternalPolicyProviderVisitor mv;
   mv.Visit(forced_extensions, expected_extensions);
 }
 
 }  // namespace extensions