Remove the last usages of PrefObserver outside of Prefs.

chrome/browser/prefs/scoped_user_pref_update_unittest.cc

Index: chrome/browser/prefs/scoped_user_pref_update_unittest.cc
diff --git a/chrome/browser/prefs/scoped_user_pref_update_unittest.cc b/chrome/browser/prefs/scoped_user_pref_update_unittest.cc
index f5e6927bd0b2c7260f160df1beb6d952d8784b21..c06d5ef945524403cc360d37bf140e744fde746d 100644
--- a/chrome/browser/prefs/scoped_user_pref_update_unittest.cc
+++ b/chrome/browser/prefs/scoped_user_pref_update_unittest.cc
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/prefs/public/pref_change_registrar.h"
-#include "chrome/browser/prefs/pref_observer_mock.h"
+#include "chrome/browser/prefs/mock_pref_change_callback.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/test/base/testing_pref_service.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -14,13 +14,14 @@ using testing::Mock;
 
 class ScopedUserPrefUpdateTest : public testing::Test {
  public:
+  ScopedUserPrefUpdateTest() : observer_(&prefs_) {}
   ~ScopedUserPrefUpdateTest() {}
 
  protected:
   virtual void SetUp() {
     prefs_.RegisterDictionaryPref(kPref, PrefService::UNSYNCABLE_PREF);
     registrar_.Init(&prefs_);
-    registrar_.Add(kPref, &observer_);
+    registrar_.Add(kPref, observer_.GetCallback());
   }
 
   static const char kPref[];
@@ -28,7 +29,7 @@ class ScopedUserPrefUpdateTest : public testing::Test {
   static const char kValue[];
 
   TestingPrefService prefs_;
-  PrefObserverMock observer_;
+  MockPrefChangeCallback observer_;
   PrefChangeRegistrar registrar_;
 };
 
@@ -42,7 +43,7 @@ TEST_F(ScopedUserPrefUpdateTest, RegularUse) {
   expected_dictionary.SetString(kKey, kValue);
 
   {
-    EXPECT_CALL(observer_, OnPreferenceChanged(_, _)).Times(0);
+    EXPECT_CALL(observer_, OnPreferenceChanged(_)).Times(0);
     DictionaryPrefUpdate update(&prefs_, kPref);
     DictionaryValue* value = update.Get();
     ASSERT_TRUE(value);
@@ -58,7 +59,7 @@ TEST_F(ScopedUserPrefUpdateTest, RegularUse) {
     EXPECT_TRUE(expected_dictionary.Equals(current_value));
 
     // Now we are leaving the scope of the update so we should be notified.
-    observer_.Expect(&prefs_, kPref, &expected_dictionary);
+    observer_.Expect(kPref, &expected_dictionary);
   }
   Mock::VerifyAndClearExpectations(&observer_);
 
@@ -69,7 +70,7 @@ TEST_F(ScopedUserPrefUpdateTest, RegularUse) {
 
 TEST_F(ScopedUserPrefUpdateTest, NeverTouchAnything) {
   const DictionaryValue* old_value = prefs_.GetDictionary(kPref);
-  EXPECT_CALL(observer_, OnPreferenceChanged(_, _)).Times(0);
+  EXPECT_CALL(observer_, OnPreferenceChanged(_)).Times(0);
   {
     DictionaryPrefUpdate update(&prefs_, kPref);
   }