IndexedDB: Recycle cursor objects when calling continue().

content/browser/in_process_webkit/indexed_db_dispatcher_host.h

Index: content/browser/in_process_webkit/indexed_db_dispatcher_host.h
diff --git a/content/browser/in_process_webkit/indexed_db_dispatcher_host.h b/content/browser/in_process_webkit/indexed_db_dispatcher_host.h
index 874587c24729fe195e820592c3e3258f3397e8f8..a689f49e3e834976edeeee6b370e22291d6797c0 100644
--- a/content/browser/in_process_webkit/indexed_db_dispatcher_host.h
+++ b/content/browser/in_process_webkit/indexed_db_dispatcher_host.h
@@ -65,6 +65,16 @@ class IndexedDBDispatcherHost : public BrowserMessageFilter {
   int32 Add(WebKit::WebIDBTransaction* idb_transaction, const GURL& origin_url);
   int32 Add(WebKit::WebDOMStringList* domStringList);
 
+  WebKit::WebIDBCursor* getCursorFromId(int32 cursor_id) {
+    return GetOrTerminateProcess(&cursor_dispatcher_host_->map_, cursor_id);
+  }
+
+  int32 GetAndConsumeCursorIdForPendingContinue(int32 response_id) {
+    int32 cursor_id = pending_cursor_continues_[response_id];
+    pending_cursor_continues_.erase(response_id);
+    return cursor_id;
+  }
+
  private:
   virtual ~IndexedDBDispatcherHost();
 
@@ -269,6 +279,7 @@ class IndexedDBDispatcherHost : public BrowserMessageFilter {
     WebIDBTransactionIDToSizeMap transaction_size_map_;
   };
 
+
   // Data shared between renderer processes with the same browser context.
   scoped_refptr<WebKitContext> webkit_context_;
 
@@ -282,6 +293,9 @@ class IndexedDBDispatcherHost : public BrowserMessageFilter {
   // Used to dispatch messages to the correct view host.
   int process_id_;
 
+  // Map from response id to cursor id. Access on WebKit thread only.
+  std::map<int32,int32> pending_cursor_continues_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(IndexedDBDispatcherHost);
 };