Remove source line tracking from MediaList and related DevTools code

Source/devtools/front_end/CSSStyleModel.js

 /*
  * Copyright (C) 2010 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 1188 matching lines @@
 /**
  * @constructor
  * @param {CSSAgent.CSSMedia} payload
  * @param {!NetworkAgent.FrameId} frameId
  */
 WebInspector.CSSMedia = function(payload, frameId)
 {
     this.text = payload.text;
     this.source = payload.source;
     this.sourceURL = payload.sourceURL || "";
-    this.sourceLine = typeof payload.sourceLine === "undefined" || this.source === "linkedSheet" ? -1 : payload.sourceLine;
     this.range = payload.range;
     this.frameId = frameId;
 }
 
 WebInspector.CSSMedia.Source = {
     LINKED_SHEET: "linkedSheet",
     INLINE_SHEET: "inlineSheet",
     MEDIA_RULE: "mediaRule",
     IMPORT_RULE: "importRule"
 };
@@ skipping 439 matching lines @@
 
         if (!namedFlow)
             return null;
         return namedFlow;
     }
 }
 /**
  * @type {WebInspector.CSSStyleModel}
  */
 WebInspector.cssModel = null;