[Extensions] Enable promise support on the action API

This CL changes over the json schema to use the new returns_async format
to define callbacks, enabling promise support on those APIs.

Note: action.setIcon does not yet support promises as it uses a custom
hook. Promise support for APIs using custom hooks will be added at a
later time.

Bug: 328932
Change-Id: I3271db95514a5410ae4e361b514c8932dad1d85f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2514745Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Tim Judkins <tjudkins@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826841}

chrome/common/extensions/api/action.json

@@ -37,12 +37,12 @@
             "description": "Limits the change to when a particular tab is selected. Automatically resets when the tab is closed."
           }
         }
-      }, {
-        "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [],
         "optional": true
-      }]
+      }
     }, {
       "name": "getTitle",
       "type": "function",
@@ -50,14 +50,14 @@
       "parameters": [{
         "name": "details",
         "$ref": "TabDetails"
-      }, {
-        "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [{
           "name": "result",
           "type": "string"
         }]
-      }]
+      }
     }, {
       "name": "setIcon",
       "type": "function",
@@ -103,8 +103,7 @@
       "name": "setPopup",
       "type": "function",
       "description": "Sets the html document to be opened as a popup when the user clicks on the action's icon.",
-      "parameters": [
-        {
+      "parameters": [{
         "name": "details",
         "type": "object",
         "properties": {
@@ -119,13 +118,12 @@
             "description": "The html file to show in a popup.  If set to the empty string (''), no popup is shown."
           }
         }
-        }, {
-          "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [],
         "optional": true
       }
-      ]
     }, {
       "name": "getPopup",
       "type": "function",
@@ -134,9 +132,9 @@
         {
           "name": "details",
           "$ref": "TabDetails"
-        },
-        {
-          "type": "function",
+        }
+      ],
+      "returns_async": {
         "name": "callback",
         "parameters": [
           {
@@ -145,7 +143,6 @@
           }
         ]
       }
-      ]
     }, {
       "name": "setBadgeText",
       "type": "function",
@@ -165,12 +162,12 @@
             "description": "Limits the change to when a particular tab is selected. Automatically resets when the tab is closed."
           }
         }
-      }, {
-        "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [],
         "optional": true
-      }]
+      }
     }, {
       "name": "getBadgeText",
       "type": "function",
@@ -178,14 +175,14 @@
       "parameters": [{
         "name": "details",
         "$ref": "TabDetails"
-      }, {
-        "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [{
           "name": "result",
           "type": "string"
         }]
-      }]
+      }
     }, {
       "name": "setBadgeBackgroundColor",
       "type": "function",
@@ -208,12 +205,12 @@
             "description": "Limits the change to when a particular tab is selected. Automatically resets when the tab is closed."
           }
         }
-      }, {
-        "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [],
         "optional": true
-      }]
+      }
     }, {
       "name": "getBadgeBackgroundColor",
       "type": "function",
@@ -221,14 +218,14 @@
       "parameters": [{
         "name": "details",
         "$ref": "TabDetails"
-      }, {
-        "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [{
           "name": "result",
           "$ref": "browserAction.ColorArray"
         }]
-      }]
+      }
     }, {
       "name": "enable",
       "type": "function",
@@ -239,12 +236,12 @@
         "name": "tabId",
         "minimum": 0,
         "description": "The id of the tab for which you want to modify the action."
-      }, {
-        "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [],
         "optional": true
-      }]
+      }
     }, {
       "name": "disable",
       "type": "function",
@@ -255,12 +252,12 @@
         "name": "tabId",
         "minimum": 0,
         "description": "The id of the tab for which you want to modify the action."
-      }, {
-        "type": "function",
+      }],
+      "returns_async": {
         "name": "callback",
         "parameters": [],
         "optional": true
-      }]
+      }
     }],
     "events": [{
       "name": "onClicked",