Remove InstallTracker's extension installed, uninstalled observers.

chrome/browser/extensions/install_observer.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_INSTALL_OBSERVER_H_
 #define CHROME_BROWSER_EXTENSIONS_INSTALL_OBSERVER_H_
 
 #include <string>
 
 #include "ui/gfx/image/image_skia.h"
@@ skipping 41 matching lines @@
   virtual void OnBeginCrxInstall(const std::string& extension_id) {}
 
   // Called when installation of a crx has completed (either successfully or
   // not).
   virtual void OnFinishCrxInstall(const std::string& extension_id,
                                   bool success) {}
 
   // Called if the extension fails to install.
   virtual void OnInstallFailure(const std::string& extension_id) {}
 
-  // Called if the installation succeeds.
-  virtual void OnExtensionInstalled(const Extension* extension) {}
-
-  // Called when an extension is [Uninstalled] or an app is
-  // installed to the app list. These are simply forwarded from the
-  // chrome::NOTIFICATIONs.
-  virtual void OnExtensionUninstalled(const Extension* extension) {}
+  // Called when an extension or an app is installed to the app list. These are
+  // simply forwarded from the chrome::NOTIFICATIONs.
   virtual void OnDisabledExtensionUpdated(const Extension* extension) {}
   virtual void OnAppInstalledToAppList(const std::string& extension_id) {}
 
   // Called when the app list is reordered.
   virtual void OnAppsReordered() {}
 
   // Notifies observers that the observed object is going away.
   virtual void OnShutdown() {}
 
  protected:
   virtual ~InstallObserver() {}
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_INSTALL_OBSERVER_H_