MD History: update (instead of re-create) data sources on sign in change

content/browser/webui/url_data_manager_backend.h

Index: content/browser/webui/url_data_manager_backend.h
diff --git a/content/browser/webui/url_data_manager_backend.h b/content/browser/webui/url_data_manager_backend.h
index f8ae89024947ae303b5f812d2bbeef3b22d4112f..053b9b5d45497896b98046965a073e839a54a434 100644
--- a/content/browser/webui/url_data_manager_backend.h
+++ b/content/browser/webui/url_data_manager_backend.h
@@ -13,6 +13,7 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/supports_user_data.h"
+#include "base/values.h"
 #include "content/browser/webui/url_data_manager.h"
 #include "content/public/browser/url_data_source.h"
 #include "net/url_request/url_request_job_factory.h"
@@ -52,6 +53,9 @@ class URLDataManagerBackend : public base::SupportsUserData::Data {
   // Adds a DataSource to the collection of data sources.
   void AddDataSource(URLDataSourceImpl* source);
 
+  void UpdateWebUIDataSource(const std::string& source_name,
+                             const base::DictionaryValue& update);
+
   // DataSource invokes this. Sends the data to the URLRequest. |bytes| may be
   // null, which signals an error handling the request.
   void DataAvailable(RequestID request_id, base::RefCountedMemory* bytes);