Makes a handful of DataSources not replace the existing

chrome/browser/webui/chrome_url_data_manager.h

 // Copyright (c) 2011 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_WEBUI_CHROME_URL_DATA_MANAGER_H_
 #define CHROME_BROWSER_WEBUI_CHROME_URL_DATA_MANAGER_H_
 #pragma once
 
-#include <map>
-#include <set>
 #include <string>
 
 #include "base/ref_counted.h"
 #include "base/task.h"
 #include "chrome/browser/browser_thread.h"
 
 class ChromeURLDataManagerBackend;
 class DictionaryValue;
 class FilePath;
 class MessageLoop;
@@ skipping 67 matching lines @@
     // message_loop_, which generally results in processing on the UI thread.
     // It may be beneficial to return NULL for requests that are safe to handle
     // directly on the IO thread.  This can improve performance by satisfying
     // such requests more rapidly when there is a large amount of UI thread
     // contention.
     virtual MessageLoop* MessageLoopForRequestPath(const std::string& path)
         const;
 
     const std::string& source_name() const { return source_name_; }
 
+    // Returns true if this DataSource should replace an existing DataSource
+    // with the same name that has already been registered. The default is
+    // true.
+    //
+    // WARNING: this is invoked on the IO thread.
+    //
+    // TODO: nuke this and convert all callers to not replace.
+    virtual bool ShouldReplaceExistingSource() const;
+
     static void SetFontAndTextDirection(DictionaryValue* localized_strings);
 
    protected:
     virtual ~DataSource();
 
    private:
     friend class ChromeURLDataManagerBackend;
     friend class ChromeURLDataManager;
     friend class DeleteTask<DataSource>;
 
@@ skipping 29 matching lines @@
   //
   // If |AddDataSource| is called more than once for a particular name it will
   // release the old |DataSource|, most likely resulting in it getting deleted
   // as there are no other references to it. |DataSource| uses the
   // |DeleteOnUIThread| trait to insure that the destructor is called on the UI
   // thread. This is necessary as some |DataSource|s notably |FileIconSource|
   // and |WebUIFavIconSource|, have members that will DCHECK if they are not
   // destructed in the same thread as they are constructed (the UI thread).
   void AddDataSource(DataSource* source);
 
-  // Returns true if a DataSource has been added with the given name.
-  bool IsRegistered(const std::string& name);
-
   // Deletes any data sources no longer referenced. This is normally invoked
   // for you, but can be invoked to force deletion (such as during shutdown).
   static void DeleteDataSources();
 
  private:
   typedef std::vector<const ChromeURLDataManager::DataSource*> DataSources;
 
   // If invoked on the UI thread the DataSource is deleted immediatlye,
   // otherwise it is added to |data_sources_| and a task is scheduled to handle
   // deletion on the UI thread. See note abouve DeleteDataSource for more info.
   static void DeleteDataSource(const DataSource* data_source);
 
   // Returns true if |data_source| is scheduled for deletion (|DeleteDataSource|
   // was invoked).
   static bool IsScheduledForDeletion(const DataSource* data_source);
 
   Profile* profile_;
 
-  // Names of the DataSources that have been registered.
-  // By caching this rather than accessing ChromeURLDataManagerBackend we avoid
-  // a delay between when AddDataSource is invoked and when the IO thread
-  // processes it.
-  std::set<std::string> registered_source_names_;
-
   // Lock used when accessing |data_sources_|.
   static base::Lock delete_lock_;
 
   // |data_sources_| that are no longer referenced and scheduled for deletion.
   static DataSources* data_sources_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeURLDataManager);
 };
 
 #endif  // CHROME_BROWSER_WEBUI_CHROME_URL_DATA_MANAGER_H_