DevTools: Add support for adding source map to a script from the DevTools window.

Source/devtools/front_end/sdk/CompilerScriptMapping.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 89 matching lines @@
             return null;
         return this._debuggerModel.createRawLocation(script, /** @type {number} */ (entry[0]), /** @type {number} */ (entry[1]));
     },
 
     /**
      * @param {!WebInspector.Script} script
      */
     addScript: function(script)
     {
         script.pushSourceMapping(this);
+        script.addEventListener(WebInspector.Script.Events.SourceMapURLAdded, this._sourceMapURLAdded.bind(this));
+        this._processScript(script);
+    },
+
+    /**
+     * @param {!WebInspector.Event} event
+     */
+    _sourceMapURLAdded: function(event)
+    {
+        var script = /** @type {!WebInspector.Script} */ (event.target);
+        this._processScript(script);
+    },
+
+    /**
+     * @param {!WebInspector.Script} script
+     */
+    _processScript: function(script)
+    {
         this.loadSourceMapForScript(script, sourceMapLoaded.bind(this));
 
         /**
          * @param {?WebInspector.SourceMap} sourceMap
          * @this {WebInspector.CompilerScriptMapping}
          */
         function sourceMapLoaded(sourceMap)
         {
             if (!sourceMap)
                 return;
@@ skipping 156 matching lines @@
         this._sourceMapForScriptId = {};
         this._scriptForSourceMap.clear();
         this._sourceMapForURL.clear();
     },
 
     dispose: function()
     {
         this._workspace.removeEventListener(WebInspector.Workspace.Events.UISourceCodeAdded, this._uiSourceCodeAddedToWorkspace, this);
     }
 }