Added missing names in extension api jsons

chrome/common/extensions/api/experimental.downloads.json

 [
   {
     "namespace": "experimental.downloads",
     "nodoc": "true",
     "events": [
       {
         "name": "onCreated",
         "type": "function",
         "description": "This event fires with the DownloadItem object when a download begins.",
         "parameters": [
-          {"$ref": "DownloadItem"}
+          {"name": "downloadItem", "$ref": "DownloadItem"}
         ]
       },
       {
         "name": "onChanged",
         "type": "function",
         "description": "When any of a DownloadItem's properties except |bytesReceived| changes, this event fires with the download id and an object containing the properties that changed.",
         "parameters": [
-          {"$ref": "DownloadDelta"}
+          {"name": "downloadDelta", "$ref": "DownloadDelta"}
         ]
       },
       {
         "name": "onErased",
         "type": "function",
         "description": "Fires with the download id when a download is erased from history.",
         "parameters": [
           {"type": "integer", "name": "downloadId"}
         ]
       }
@@ skipping 398 matching lines @@
           }
         }
       }
     ],
     "functions": [
       {
         "name": "download",
         "type": "function",
         "description": "Download a URL. If the URL uses the HTTP[S] protocol, then the request will include all cookies currently set for its hostname. If the download started successfully, |callback| will be called with the new DownloadItem’s |id|. If there was an error starting the download, then |callback| will be called with |downloadId|=undefined and chrome.extension.lastError will be set. If the URL’s hostname is not specified in the |permissions| section of the extension’s manifest, then the |chrome.extensions.lastError| object will indicate that the extension does not have permission to access that hostname.",
         "parameters": [
-          {"$ref": "DownloadOptions"},
+          {"name": "options", "$ref": "DownloadOptions"},
           {
             "name": "callback",
             "type": "function",
             "optional": true,
             "parameters": [
               {"name": "id", "type": "integer"}
             ]
           }
         ]
       },
       {
         "name": "search",
         "type": "function",
         "description": "Find DownloadItems. Set |query| to the empty object to get all DownloadItems. To get a specific DownloadItem, set only the |id| field.",
         "parameters": [
-          {"$ref": "DownloadQuery"},
+          {"name": "query", "$ref": "DownloadQuery"},
           {
             "name": "callback",
             "type": "function",
             "optional": true,
             "parameters": [
               {"name": "items", "type": "array"}
             ]
           }
         ]
       },
       {
         "name": "erase",
         "type": "function",
         "description": "Erase matching DownloadItems from history",
         "parameters": [
-          {"$ref": "DownloadQuery"},
+          {"name": "query", "$ref": "DownloadQuery"},
           {
             "name": "callback",
             "type": "function",
             "optional": true,
             "parameters": [
               {"name": "ids", "type": "array"}
             ]
           }
         ]
       },
@@ skipping 71 matching lines @@
             "type": "function",
             "optional": true,
             "parameters": [],
             "description": "Called when the request is completed. The download is cancelled, completed, interrupted or doesn't exist anymore."
           }
         ]
       }
     ]
   }
 ]