DevTools: teach automapping to map complex sourcemap setups.

third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.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 405 matching lines @@
   _parseSources(sourceMap) {
     var sourcesList = [];
     var sourceRoot = sourceMap.sourceRoot || '';
     if (sourceRoot && !sourceRoot.endsWith('/'))
       sourceRoot += '/';
     for (var i = 0; i < sourceMap.sources.length; ++i) {
       var href = sourceRoot + sourceMap.sources[i];
       var url = Common.ParsedURL.completeURL(this._sourceMappingURL, href) || href;
       var source = sourceMap.sourcesContent && sourceMap.sourcesContent[i];
       if (url === this._compiledURL && source)
-        url += Common.UIString(' [sm]');
+        url += Common.UIString('? [sm]');
       this._sourceInfos.set(url, new SDK.TextSourceMap.SourceInfo(source, null));
       sourcesList.push(url);
     }
     sourceMap[SDK.TextSourceMap._sourcesListSymbol] = sourcesList;
   }
 
   /**
    * @param {!SDK.SourceMapV3} map
    * @param {number} lineNumber
    * @param {number} columnNumber
@@ skipping 152 matching lines @@
    * @param {?string} content
    * @param {?Array<!SDK.SourceMapEntry>} reverseMappings
    */
   constructor(content, reverseMappings) {
     this.content = content;
     this.reverseMappings = reverseMappings;
   }
 };
 
 SDK.TextSourceMap._sourcesListSymbol = Symbol('sourcesList');