Removing PrefObserver usage, batch 4.

chrome/browser/extensions/api/font_settings/font_settings_api.h

Index: chrome/browser/extensions/api/font_settings/font_settings_api.h
diff --git a/chrome/browser/extensions/api/font_settings/font_settings_api.h b/chrome/browser/extensions/api/font_settings/font_settings_api.h
index a81c7a9dc2a025979e789459ebc5bc76eb1169d6..38ec94f38b0ef90b2bb68c620e36693fc487bc22 100644
--- a/chrome/browser/extensions/api/font_settings/font_settings_api.h
+++ b/chrome/browser/extensions/api/font_settings/font_settings_api.h
@@ -13,7 +13,6 @@
 #include <utility>
 
 #include "base/prefs/public/pref_change_registrar.h"
-#include "base/prefs/public/pref_observer.h"
 #include "chrome/browser/extensions/extension_function.h"
 #include "chrome/browser/prefs/pref_service.h"
 
@@ -21,7 +20,7 @@ namespace extensions {
 
 // This class observes pref changed events on a profile and dispatches the
 // corresponding extension API events to extensions.
-class FontSettingsEventRouter : public PrefObserver {
+class FontSettingsEventRouter {
  public:
   // Constructor for observing pref changed events on |profile|. Stores a
   // pointer to |profile| but does not take ownership. |profile| must be
@@ -44,17 +43,14 @@ class FontSettingsEventRouter : public PrefObserver {
                         const char* event_name,
                         const char* key);
 
-  // PrefObserver implementation.
-  virtual void OnPreferenceChanged(PrefServiceBase* service,
-                                   const std::string& pref_name) OVERRIDE;
+  void OnPreferenceChanged(const std::string& pref_name);
 
   // Dispatches a changed event for the font setting for |generic_family| and
   // |script| to extensions. The new value of the setting is the value of
   // browser pref |pref_name|. If the pref changed on the incognito profile,
   // |incognito| must be set to true for extensions to get the appropriate
   // event.
-  void OnFontNamePrefChanged(PrefServiceBase* pref_service,
-                             const std::string& pref_name,
+  void OnFontNamePrefChanged(const std::string& pref_name,
                              const std::string& generic_family,
                              const std::string& script,
                              bool incognito);
@@ -65,8 +61,7 @@ class FontSettingsEventRouter : public PrefObserver {
   // under the key |key|. If the pref changed on the incognito profile,
   // |incognito| must be set to true for extensions to get the appropriate
   // event.
-  void OnFontPrefChanged(PrefServiceBase* pref_service,
-                         const std::string& pref_name,
+  void OnFontPrefChanged(const std::string& pref_name,
                          const std::string& event_name,
                          const std::string& key,
                          bool incognito);