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

third_party/WebKit/Source/devtools/front_end/sdk/CSSStyleSheetHeader.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @constructor
  * @implements {WebInspector.ContentProvider}
  * @param {!WebInspector.CSSModel} cssModel
  * @param {!CSSAgent.CSSStyleSheetHeader} payload
  */
@@ skipping 15 matching lines @@
     this.setSourceMapURL(payload.sourceMapURL);
 }
 
 WebInspector.CSSStyleSheetHeader.prototype = {
     /**
      * @return {!WebInspector.ContentProvider}
      */
     originalContentProvider: function()
     {
         if (!this._originalContentProvider) {
-            var originalContentPromise = this._cssModel.originalStyleSheetText(this);
-            this._originalContentProvider = new WebInspector.StaticContentProvider(this.contentURL(), this.contentType(), originalContentPromise);
+            var lazyContent = this._cssModel.originalStyleSheetText.bind(this._cssModel, this);
+            this._originalContentProvider = new WebInspector.StaticContentProvider(this.contentURL(), this.contentType(), lazyContent);
         }
         return this._originalContentProvider;
     },
 
     /**
      * @param {string=} sourceMapURL
      */
     setSourceMapURL: function(sourceMapURL)
     {
         var completeSourceMapURL = this.sourceURL && sourceMapURL ? WebInspector.ParsedURL.completeURL(this.sourceURL, sourceMapURL) : null;
@@ skipping 163 matching lines @@
          * @param {?string} content
          */
         function performSearch(content)
         {
             var searchResults = content ? WebInspector.ContentProvider.performSearchInContent(content, query, caseSensitive, isRegex) : [];
             callback(searchResults);
         }
 
         this.requestContent().then(performSearch);
     }
-}
+}