experimental.popup support for tab-content-viewed extensions

chrome/common/extensions/api/extension_api.json

 [
   {
     "namespace": "extension",
     "types": [
       {
         "id": "MessageSender",
         "type": "object",
         "description": "An object containing information about the script context that sent a message or request.",
         "properties": {
           "tab": {"$ref": "Tab", "optional": true, "description":"This property will <b>only</b> be present when the connection was opened from a tab or content script."},
@@ skipping 1624 matching lines @@
   },
   {
     "namespace": "experimental.popup",
     "nodoc": true,
     "types": [],
     "functions": [
       {
         "name": "show",
         "type": "function",
         "description": "Displays a pop-up window hosting an extension view.",
-        "customHandler": "true",
         "parameters": [
           {
             "type": "string",
             "name": "url",
             "description": "The URL of the contents to which the pop-up will be navigated."
           },
           {
             "type": "object",
             "name": "showDetails",
             "properties": {
               "relativeTo": {
                 "type": "object",
                 "properties": {},
                 "additionalProperties": { "type": "any" },
                 "isInstanceOf": "HTMLElement",
-                "description": "The HTMLElement whose position which serve as the anchor position of the popup."
+                "description": "A HTML DOM object to which the pop-up's position will be made relative."
               }
             }
           },
           {
             "type": "function",
             "name": "callback",
             "parameters": []
           }
         ]
       },
       {
-        "name": "getAnchorWindow",
+        "name": "getParentWindow",
         "type": "function",
         "description": "Returns a reference to the window object of the extension view that launched the popup.",
         "parameters": [],
         "returns": {
           "type": "object",
           "isInstanceOf": "DOMWindow",
           "properties": {},
           "additionalProperties": { "type": "any" }
         }
       }
@@ skipping 56 matching lines @@
         "type": "function",
         "description": "Logs a message during internal unit testing.",
         "parameters": [
           {"type": "string", "name": "message"}
         ]
       }
     ],
     "events": []
   }
 ]