[DevTools] Fix location.script().sourceURL

third_party/WebKit/Source/devtools/front_end/sources/SourceMapNamesResolver.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 WebInspector.SourceMapNamesResolver = {};
 
 WebInspector.SourceMapNamesResolver._cachedMapSymbol = Symbol("cache");
 WebInspector.SourceMapNamesResolver._cachedIdentifiersSymbol = Symbol("cachedIdentifiers");
 
 /**
@@ skipping 245 matching lines @@
  * @return {!Promise<string>}
  */
 WebInspector.SourceMapNamesResolver._resolveExpression = function(callFrame, uiSourceCode, lineNumber, startColumnNumber, endColumnNumber)
 {
     var target = callFrame.target();
     var rawLocation = WebInspector.debuggerWorkspaceBinding.uiLocationToRawLocation(target, uiSourceCode, lineNumber, startColumnNumber);
     if (!rawLocation)
         return Promise.resolve("");
 
     var script = rawLocation.script();
+    if (!script)
+        return Promise.resolve("");
     var sourceMap = WebInspector.debuggerWorkspaceBinding.sourceMapForScript(script);
     if (!sourceMap)
         return Promise.resolve("");
 
     return script.requestContent().then(onContent);
 
     /**
      * @param {?string} content
      * @return {!Promise<string>}
      */
@@ skipping 293 matching lines @@
      * @return {boolean}
      */
     isNode: function()
     {
         return this._object.isNode();
     },
 
     __proto__: WebInspector.RemoteObject.prototype
 }