Remove PrefObserver usage, batch 3.

chrome/browser/content_settings/content_settings_pref_provider.cc

Index: chrome/browser/content_settings/content_settings_pref_provider.cc
diff --git a/chrome/browser/content_settings/content_settings_pref_provider.cc b/chrome/browser/content_settings/content_settings_pref_provider.cc
index e5ad337a5d9d2231b5dce62913b37d961433a93c..eb6135f7c507a3e8c30773537de33828f7f7f499 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider.cc
+++ b/chrome/browser/content_settings/content_settings_pref_provider.cc
@@ -120,7 +120,10 @@ PrefProvider::PrefProvider(PrefService* prefs,
   }
 
   pref_change_registrar_.Init(prefs_);
-  pref_change_registrar_.Add(prefs::kContentSettingsPatternPairs, this);
+  pref_change_registrar_.Add(
+      prefs::kContentSettingsPatternPairs,
+      base::Bind(&PrefProvider::OnContentSettingsPatternPairsChanged,
+                 base::Unretained(this)));
 }
 
 bool PrefProvider::SetWebsiteSetting(
@@ -217,23 +220,6 @@ void PrefProvider::ClearAllContentSettingsRules(
                   std::string());
 }
 
-void PrefProvider::OnPreferenceChanged(PrefServiceBase* service,
-                                       const std::string& name) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK_EQ(prefs_, service);
-  DCHECK_EQ(std::string(prefs::kContentSettingsPatternPairs), name);
-
-  if (updating_preferences_)
-    return;
-
-  ReadContentSettingsFromPref(true);
-
-  NotifyObservers(ContentSettingsPattern(),
-                  ContentSettingsPattern(),
-                  CONTENT_SETTINGS_TYPE_DEFAULT,
-                  std::string());
-}
-
 PrefProvider::~PrefProvider() {
   DCHECK(!prefs_);
 }
@@ -384,6 +370,20 @@ void PrefProvider::ReadContentSettingsFromPref(bool overwrite) {
   }
 }
 
+void PrefProvider::OnContentSettingsPatternPairsChanged() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (updating_preferences_)
+    return;
+
+  ReadContentSettingsFromPref(true);
+
+  NotifyObservers(ContentSettingsPattern(),
+                  ContentSettingsPattern(),
+                  CONTENT_SETTINGS_TYPE_DEFAULT,
+                  std::string());
+}
+
 void PrefProvider::UpdatePatternPairsSettings(
       const ContentSettingsPattern& primary_pattern,
       const ContentSettingsPattern& secondary_pattern,