DevTools: promisify ContentProvider.requestContent and all its clients.

third_party/WebKit/Source/devtools/front_end/resources/FileContentView.js

 /*
  * Copyright (C) 2012 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 51 matching lines @@
      */
     _metadataReceived: function(errorCode, metadata)
     {
         if (errorCode || !metadata)
             return;
 
         if (this._content) {
             if (!this._content.updateMetadata(metadata))
                 return;
             var sourceFrame = /** @type {!WebInspector.SourceFrame} */ (this._innerView);
-            this._content.requestContent(sourceFrame.setContent.bind(sourceFrame));
+            this._content.requestContent().then(sourceFrame.setContent.bind(sourceFrame));
         } else {
             this._innerView.detach();
             this._content = new WebInspector.FileContentView.FileContentProvider(this._file, metadata);
             var sourceFrame = new WebInspector.SourceFrame(this._content);
             sourceFrame.setHighlighterType(this._file.resourceType.canonicalMimeType());
             this._innerView = sourceFrame;
             this._innerView.show(this.element);
         }
     },
 
@@ skipping 35 matching lines @@
      * @override
      * @return {!WebInspector.ResourceType}
      */
     contentType: function()
     {
         return this._file.resourceType;
     },
 
     /**
      * @override
-     * @param {function(?string)} callback
+     * @return {!Promise<?string>}
      */
-    requestContent: function(callback)
+    requestContent: function()
     {
+        var callback;
+        var promise = new Promise(fulfill => callback = fulfill);
         var size = /** @type {number} */ (this._metadata.size);
         this._file.requestFileContent(true, 0, size, this._charset || "", this._fileContentReceived.bind(this, callback));
+        return promise;
     },
 
     /**
      * @param {function(?string)} callback
      * @param {number} errorCode
      * @param {string=} content
      * @param {boolean=} base64Encoded
      * @param {string=} charset
      */
     _fileContentReceived: function(callback, errorCode, content, base64Encoded, charset)
@@ skipping 24 matching lines @@
      * @return {boolean}
      */
     updateMetadata: function(metadata)
     {
         if (this._metadata.modificationTime >= metadata.modificationTime)
             return false;
         this._metadata = metadata.modificationTime;
         return true;
     }
 }