Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/ui/webui/options/preferences_browsertest.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/ui/webui/options/preferences_browsertest.h"
 
 #include <iostream>
 #include <sstream>
 
 #include "base/json/json_reader.h"
@@ skipping 144 matching lines @@
       L""
       L"  finishObservingAndReply: function() {"
       L"    this.sentinelValue_ = !this.sentinelValue_;"
       L"    Preferences.setBooleanPref(this.sentinelName_, this.sentinelValue_,"
       L"                               true);"
       L"  }"
       L"};"));
 }
 
 // Forwards notifications received when pref values change in the backend.
-void PreferencesBrowserTest::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  ASSERT_EQ(chrome::NOTIFICATION_PREF_CHANGED, type);
-  ASSERT_EQ(pref_service_, content::Source<PrefService>(source).ptr());
-  const std::string& name = *content::Details<std::string>(details).ptr();
-  OnCommit(pref_service_->FindPreference(name.c_str()));
+void PreferencesBrowserTest::OnPreferenceChanged(PrefServiceBase* service,
+                                                 const std::string& pref_name) {
+  ASSERT_EQ(pref_service_, service);
+  OnCommit(pref_service_->FindPreference(pref_name.c_str()));
 }
 
 // Sets up a mock user policy provider.
 void PreferencesBrowserTest::SetUpInProcessBrowserTestFixture() {
   EXPECT_CALL(policy_provider_, IsInitializationComplete())
       .WillRepeatedly(Return(true));
   policy::BrowserPolicyConnector::SetPolicyProviderForTesting(
       &policy_provider_);
 };
 
@@ skipping 549 matching lines @@
   // Do not set the Boolean pref. It will toogle automatically.
   for (size_t i = 1; i < pref_names_.size(); ++i)
     chromeos::proxy_cros_settings_parser::SetProxyPrefValue(
         profile, pref_names_[i], non_default_values_[i]->DeepCopy());
   SetupJavaScriptTestEnvironment(pref_names_, &observed_json);
   VerifyObservedPrefs(observed_json, pref_names_, non_default_values_,
                       "", false, false);
 }
 
 #endif