Delay request loading until all user scripts that request depends on are ready.

chrome/browser/extensions/user_script_master.h

 // Copyright (c) 2008 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_USER_SCRIPT_MASTER_H_
 #define CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_H_
 
 #include <vector>
 
 #include "base/directory_watcher.h"
@@ skipping 10 matching lines @@
 // Manages a segment of shared memory that contains the user scripts the user
 // has installed.  Lives on the UI thread.
 class UserScriptMaster : public base::RefCounted<UserScriptMaster>,
                          public DirectoryWatcher::Delegate,
                          public NotificationObserver {
  public:
   // For testability, the constructor takes the MessageLoop to run the
   // script-reloading worker on as well as the path the scripts live in.
   // These are normally the file thread and a directory inside the profile.
   UserScriptMaster(MessageLoop* worker, const FilePath& script_dir);
-  ~UserScriptMaster();
+  virtual ~UserScriptMaster();
 
   // Add a watched directory. All scripts will be reloaded when any file in
   // this directory changes.
   void AddWatchedPath(const FilePath& path);
 
   // Kicks off a process on the file thread to reload scripts from disk
   // into a new chunk of shared memory and notify renderers.
-  void StartScan();
+  virtual void StartScan();
 
   // Gets the segment of shared memory for the scripts.
   base::SharedMemory* GetSharedMemory() const {
     return shared_memory_.get();
   }
 
   // Called by the script reloader when new scripts have been loaded.
   void NewScriptsAvailable(base::SharedMemory* handle);
 
   // Return true if we have any scripts ready.
@@ skipping 104 matching lines @@
 
   // If the script directory is modified while we're rescanning it, we note
   // that we're currently mid-scan and then start over again once the scan
   // finishes.  This boolean tracks whether another scan is pending.
   bool pending_scan_;
 
   DISALLOW_COPY_AND_ASSIGN(UserScriptMaster);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_H_