Draft change to use base::Closure instead of PrefObserver in PrefChangeRegistrar.

chrome/browser/extensions/extension_prefs_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 "extension_prefs_unittest.h"
 
 #include "base/basictypes.h"
 #include "base/path_service.h"
 #include "base/prefs/public/pref_change_registrar.h"
 #include "base/scoped_temp_dir.h"
@@ skipping 1108 matching lines @@
     Mock::VerifyAndClearExpectations(&observer);
     Mock::VerifyAndClearExpectations(&incognito_observer);
 
     // Uninstall.
     EXPECT_CALL(observer, OnPreferenceChanged(_, _));
     EXPECT_CALL(incognito_observer, OnPreferenceChanged(_, _));
     UninstallExtension(ext1_->id());
     Mock::VerifyAndClearExpectations(&observer);
     Mock::VerifyAndClearExpectations(&incognito_observer);
 
-    registrar.Remove(kPref1, &observer);
-    incognito_registrar.Remove(kPref1, &incognito_observer);
+    registrar.Remove(kPref1);
+    incognito_registrar.Remove(kPref1);
   }
   virtual void Verify() {
     std::string actual = prefs()->pref_service()->GetString(kPref1);
     EXPECT_EQ(kDefaultPref1, actual);
   }
 };
 TEST_F(ExtensionPrefsNotifyWhenNeeded,
     ExtensionPrefsNotifyWhenNeeded) {}
 
 // Tests disabling an extension.
@@ skipping 160 matching lines @@
     EXPECT_EQ(string16(), error16);
     EXPECT_TRUE(prefs()->UserMayModifySettings(extension_.get(), &error16));
     EXPECT_EQ(string16(), error16);
     EXPECT_FALSE(prefs()->MustRemainEnabled(extension_.get(), &error16));
     EXPECT_EQ(string16(), error16);
   }
 };
 TEST_F(ExtensionPrefsNotRequiredExtension, NotRequiredExtension) {}
 
 }  // namespace extensions