Makes a handful of DataSources not replace the existing

chrome/browser/webui/chrome_url_data_manager.h

Index: chrome/browser/webui/chrome_url_data_manager.h
diff --git a/chrome/browser/webui/chrome_url_data_manager.h b/chrome/browser/webui/chrome_url_data_manager.h
index be4cab04adf9c4a030649170c8758f5f09fe4793..ec77efbd4e1da8460e59456465ba7d7fe1009c87 100644
--- a/chrome/browser/webui/chrome_url_data_manager.h
+++ b/chrome/browser/webui/chrome_url_data_manager.h
@@ -6,8 +6,6 @@
 #define CHROME_BROWSER_WEBUI_CHROME_URL_DATA_MANAGER_H_
 #pragma once
 
-#include <map>
-#include <set>
 #include <string>
 
 #include "base/ref_counted.h"
@@ -95,6 +93,15 @@ class ChromeURLDataManager {
 
     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:
@@ -144,9 +151,6 @@ class ChromeURLDataManager {
   // 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();
@@ -165,12 +169,6 @@ class ChromeURLDataManager {
 
   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_;