[DevTools] Refactor CSS live locations.

third_party/WebKit/Source/devtools/front_end/sdk/CSSModel.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 1018 matching lines @@
   }
 };
 
 SDK.CSSLocation = class {
   /**
    * @param {!SDK.CSSStyleSheetHeader} header
    * @param {number} lineNumber
    * @param {number=} columnNumber
    */
   constructor(header, lineNumber, columnNumber) {
-    this._header = header;
+    this._cssModel = header.cssModel();
     this.styleSheetId = header.id;
     this.url = header.resourceURL();
     this.lineNumber = lineNumber;
     this.columnNumber = columnNumber || 0;
   }
 
   /**
    * @return {!SDK.CSSModel}
    */
   cssModel() {
-    return this._header.cssModel();
+    return this._cssModel;
   }
 
   /**
-   * @return {!SDK.CSSStyleSheetHeader}
+   * @return {?SDK.CSSStyleSheetHeader}
    */
   header() {
-    return this._header;
+    return this.styleSheetId ? this._cssModel.styleSheetHeaderForId(this.styleSheetId) : null;

[lushnikov, 2017/02/16 02:40:03]

don't check for this.styleSheetId

[dgozman, 2017/02/16 18:25:52]

Done.

   }
 };
 
 /**
  * @implements {Protocol.CSSDispatcher}
  * @unrestricted
  */
 SDK.CSSDispatcher = class {
   /**
    * @param {!SDK.CSSModel} cssModel
@@ skipping 99 matching lines @@
 SDK.CSSModel.InlineStyleResult = class {
   /**
    * @param {?SDK.CSSStyleDeclaration} inlineStyle
    * @param {?SDK.CSSStyleDeclaration} attributesStyle
    */
   constructor(inlineStyle, attributesStyle) {
     this.inlineStyle = inlineStyle;
     this.attributesStyle = attributesStyle;
   }
 };