Remove deprecated extension notification from theme_service

chrome/browser/themes/theme_service.h

Index: chrome/browser/themes/theme_service.h
diff --git a/chrome/browser/themes/theme_service.h b/chrome/browser/themes/theme_service.h
index b70fd74c3cdb19ec7b8f273e11b1dbbd4532cba1..94ea270c136a3b7c6b8ef06168b24b7d084c16cf 100644
--- a/chrome/browser/themes/theme_service.h
+++ b/chrome/browser/themes/theme_service.h
@@ -61,6 +61,20 @@ class ThemeService : public base::NonThreadSafe,
                      public KeyedService,
                      public ui::ThemeProvider {
  public:
+  // Receive notification when extension will be installed, loaded, unloaded.
+  class ExtensionObserver {

[Lei Zhang, 2015/03/10 19:25:52]

This class needs to:

- inherit from extensions::ExtensionRegistryObserver
- be forward declared in the private section
- be defined in the .cc file as class ThemeService::ExtensionObserver

And |extension_observer_| needs to be a scoped_ptr

+   public:
+    explicit ExtensionObserver(ThemeService& service);
+    ~ExtensionObserver();
+    void OnExtensionWillBeInstalled(const extensions::Extension* extension);
+    void OnExtensionLoaded(const extensions::Extension* extension);
+    // Not be called when reason is REASON_LOCK_ALL or REASON_UPDATED.
+    void OnExtensionUnloaded(const extensions::Extension* extension);
+
+   private:
+    ThemeService& theme_service_;
+  };
+
   // Public constants used in ThemeService and its subclasses:
   static const char* kDefaultThemeID;
 
@@ -138,6 +152,8 @@ class ThemeService : public base::NonThreadSafe,
   // owned by |this| object.
   virtual ThemeSyncableService* GetThemeSyncableService() const;
 
+  ExtensionObserver extension_observer() const;
+
   // Save the images to be written to disk, mapping file path to id.
   typedef std::map<base::FilePath, int> ImagesDiskCache;
 
@@ -248,6 +264,8 @@ class ThemeService : public base::NonThreadSafe,
 
   scoped_ptr<ThemeSyncableService> theme_syncable_service_;
 
+  ExtensionObserver extension_observer_;
+
   base::WeakPtrFactory<ThemeService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ThemeService);