Allow app_shell to run past extension manifest parsing

extensions/common/extensions_client.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 EXTENSIONS_COMMON_EXTENSIONS_CLIENT_H_
 #define EXTENSIONS_COMMON_EXTENSIONS_CLIENT_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 10 matching lines @@
 class PermissionMessageProvider;
 class PermissionsProvider;
 class URLPatternSet;
 
 // Sets up global state for the extensions system. Should be Set() once in each
 // process. This should be implemented by the client of the extensions system.
 class ExtensionsClient {
  public:
   typedef std::vector<std::string> ScriptingWhitelist;
 
+  virtual ~ExtensionsClient() {}
+
   // Initializes global state. Not done in the constructor because unit tests
   // can create additional ExtensionsClients because the utility thread runs
   // in-process.
   virtual void Initialize() = 0;
 
   // Returns a PermissionsProvider to initialize the permissions system.
   virtual const PermissionsProvider& GetPermissionsProvider() const = 0;
 
   // Returns the global PermissionMessageProvider to use to provide permission
   // warning strings.
@@ skipping 31 matching lines @@
   // Return the extensions client.
   static ExtensionsClient* Get();
 
   // Initialize the extensions system with this extensions client.
   static void Set(ExtensionsClient* client);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_EXTENSIONS_CLIENT_H_