DevTools: promisify ContentProvider.requestContent and all its clients.

third_party/WebKit/Source/devtools/front_end/sdk/ContentProviders.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 43 matching lines @@
      * @override
      * @return {!WebInspector.ResourceType}
      */
     contentType: function()
     {
         return this._contentType;
     },
 
     /**
      * @override
-     * @param {function(?string)} callback
+     * @return {!Promise<?string>}
      */
-    requestContent: function(callback)
+    requestContent: function()
     {
+        var callback;
+        var promise = new Promise(fulfill => callback = fulfill);
         WebInspector.multitargetNetworkManager.loadResource(this._sourceURL, contentLoaded.bind(this));
+        return promise;
 
         /**
          * @param {number} statusCode
          * @param {!Object.<string, string>} headers
          * @param {string} content
          * @this {WebInspector.CompilerSourceMappingContentProvider}
          */
         function contentLoaded(statusCode, headers, content)
         {
             if (statusCode >= 400) {
                 console.error("Could not load content for " + this._sourceURL + " : " + "HTTP status code: " + statusCode);
                 callback(null);
                 return;
             }
 
             callback(content);
         }
     },
 
     /**
      * @override
      * @param {string} query
      * @param {boolean} caseSensitive
      * @param {boolean} isRegex
      * @param {function(!Array.<!WebInspector.ContentProvider.SearchMatch>)} callback
      */
     searchInContent: function(query, caseSensitive, isRegex, callback)
     {
-        this.requestContent(contentLoaded);
+        this.requestContent().then(contentLoaded);
 
         /**
          * @param {?string} content
          */
         function contentLoaded(content)
         {
             if (typeof content !== "string") {
                 callback([]);
                 return;
             }
 
             callback(WebInspector.ContentProvider.performSearchInContent(content, query, caseSensitive, isRegex));
         }
     }
 }