Add ContentSettingsProvider Interface.

chrome/browser/content_settings/pref_content_settings_provider.cc

Index: chrome/browser/content_settings/pref_content_settings_provider.cc
diff --git a/chrome/browser/content_settings/pref_content_settings_provider.cc b/chrome/browser/content_settings/pref_content_settings_provider.cc
index 0afe1f91a4afdc869b0a1813c0415bd126bc8ab7..a42da857e8a9a5414ea05a94b796796766114fb8 100644
--- a/chrome/browser/content_settings/pref_content_settings_provider.cc
+++ b/chrome/browser/content_settings/pref_content_settings_provider.cc
@@ -57,6 +57,8 @@ ContentSetting ClickToPlayFixup(ContentSettingsType content_type,
 
 }  // namespace
 
+namespace content_settings {
+
 PrefContentSettingsProvider::PrefContentSettingsProvider(Profile* profile)
     : profile_(profile),
       is_off_the_record_(profile_->IsOffTheRecord()),
@@ -261,3 +263,5 @@ void PrefContentSettingsProvider::NotifyObservers(
 void PrefContentSettingsProvider::RegisterUserPrefs(PrefService* prefs) {
   prefs->RegisterDictionaryPref(prefs::kDefaultContentSettings);
 }
+
+}  // namespace content_settings