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

content/browser/webui/url_data_manager.cc

Index: content/browser/webui/url_data_manager.cc
diff --git a/content/browser/webui/url_data_manager.cc b/content/browser/webui/url_data_manager.cc
index a9ec107df4631f18239851dc13f9187d8475abe2..0a482ad8ae00ea890634668dfe676ebc7375e76f 100644
--- a/content/browser/webui/url_data_manager.cc
+++ b/content/browser/webui/url_data_manager.cc
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/lazy_instance.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/message_loop/message_loop.h"
@@ -46,6 +47,14 @@ static void AddDataSourceOnIOThread(
       data_source.get());
 }
 
+static void UpdateWebUIDataSourceOnIOThread(
+    ResourceContext* resource_context,
+    std::string source_name,
+    const base::DictionaryValue* update) {
+  GetURLDataManagerForResourceContext(resource_context)
+      ->UpdateWebUIDataSource(source_name, *update);
+}
+
 }  // namespace
 
 // static
@@ -67,6 +76,17 @@ void URLDataManager::AddDataSource(URLDataSourceImpl* source) {
                  make_scoped_refptr(source)));
 }
 
+void URLDataManager::UpdateWebUIDataSource(
+    const std::string& source_name,
+    std::unique_ptr<base::DictionaryValue> update) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&UpdateWebUIDataSourceOnIOThread,
+                 browser_context_->GetResourceContext(), source_name,
+                 base::Owned(update.release())));
+}
+
 // static
 void URLDataManager::DeleteDataSources() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
@@ -122,6 +142,14 @@ void URLDataManager::AddWebUIDataSource(BrowserContext* browser_context,
   GetFromBrowserContext(browser_context)->AddDataSource(impl);
 }
 
+void URLDataManager::UpdateWebUIDataSource(
+    BrowserContext* browser_context,
+    const std::string& source_name,
+    std::unique_ptr<base::DictionaryValue> update) {
+  GetFromBrowserContext(browser_context)
+      ->UpdateWebUIDataSource(source_name, std::move(update));
+}
+
 // static
 bool URLDataManager::IsScheduledForDeletion(
     const URLDataSourceImpl* data_source) {