Don't show post extension install bubbles when incognito mode is forced.

chrome/browser/prefs/incognito_mode_prefs.h

 // Copyright (c) 2012 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_PREFS_INCOGNITO_MODE_PREFS_H_
 #define CHROME_BROWSER_PREFS_INCOGNITO_MODE_PREFS_H_
 
 #include "base/basictypes.h"
 
 class CommandLine;
 class PrefService;
+class Profile;
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 // Specifies Incognito mode availability preferences.
 class IncognitoModePrefs {
  public:
   // Possible values for Incognito mode availability. Please, do not change
   // the order of entries since numeric values are exposed to users.
@@ skipping 25 matching lines @@
 
   // Converts in_value into the corresponding Availability value. Returns true
   // if conversion is successful (in_value is valid). Otherwise, returns false
   // and *out_value is set to ENABLED.
   static bool IntToAvailability(int in_value, Availability* out_value);
 
   // Returns true if the browser should start in incognito mode.
   static bool ShouldLaunchIncognito(const CommandLine& command_line,
                                     const PrefService* prefs);
 
+  // Returns true if |profile| can open a new Browser. This checks the incognito
+  // availability policies and verifies if the |profile| type is allowed to
+  // open new windows.
+  static bool CanOpenBrowser(Profile* profile);
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncognitoModePrefs);
 };
 
 #endif  // CHROME_BROWSER_PREFS_INCOGNITO_MODE_PREFS_H_