DevTools: do not pro-actively query all StyleSheets for their content.

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 796 matching lines @@
      */
     _ensureOriginalStyleSheetText: function(styleSheetId)
     {
         var header = this.styleSheetHeaderForId(styleSheetId);
         if (!header)
             return Promise.resolve("");
         var promise = this._originalStyleSheetText.get(header);
         if (!promise) {
             promise = this.getStyleSheetText(header.id);
             this._originalStyleSheetText.set(header, promise);
+            this._originalContentRequestedForTest(header);
         }
         return promise;
     },
 
     /**
      * @param {!WebInspector.CSSStyleSheetHeader} header
+     */
+    _originalContentRequestedForTest: function(header) { },
+
+    /**
+     * @param {!WebInspector.CSSStyleSheetHeader} header
      * @return {!Promise<string>}
      */
     originalStyleSheetText: function(header)
     {
         return this._ensureOriginalStyleSheetText(header.id);
     },
 
     /**
      * @param {!CSSAgent.CSSStyleSheetHeader} header
      */
@@ skipping 368 matching lines @@
 /**
  * @constructor
  * @param {?WebInspector.CSSStyleDeclaration} inlineStyle
  * @param {?WebInspector.CSSStyleDeclaration} attributesStyle
  */
 WebInspector.CSSModel.InlineStyleResult = function(inlineStyle, attributesStyle)
 {
     this.inlineStyle = inlineStyle;
     this.attributesStyle = attributesStyle;
 }