Split the private webstore install API into two parts....

chrome/browser/extensions/crx_installer.h

 // Copyright (c) 2009 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_CRX_INSTALLER_H_
 #define CHROME_BROWSER_EXTENSIONS_CRX_INSTALLER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 35 matching lines @@
  public:
 
   // This is pretty lame, but given the difficulty of connecting a particular
   // ExtensionFunction to a resulting download in the download manager, it's
   // currently necessary. This is the |id| of an extension to be installed
   // *by the web store only* which should not get the permissions install
   // prompt. This should only be called on the UI thread.
   // crbug.com/54916
   static void SetWhitelistedInstallId(const std::string& id);
 
+  // Returns whether |id| is whitelisted - only call this on the UI thread.
+  static bool IsIdWhitelisted(const std::string& id);
+
   // Returns whether |id| was found and removed (was whitelisted). This should
   // only be called on the UI thread.
   static bool ClearWhitelistedInstallId(const std::string& id);
 
   // Constructor.  Extensions will be unpacked to |install_directory|.
   // Extension objects will be sent to |frontend|, and any UI will be shown
   // via |client|. For silent install, pass NULL for |client|.
   CrxInstaller(const FilePath& install_directory,
                ExtensionsService* frontend,
                ExtensionInstallUI* client);
@@ skipping 160 matching lines @@
   bool allow_silent_install_;
 
   // The value of the content type header sent with the CRX.
   // Ignorred unless |require_extension_mime_type_| is true.
   std::string original_mime_type_;
 
   DISALLOW_COPY_AND_ASSIGN(CrxInstaller);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_CRX_INSTALLER_H_