DevTools: show HTTP headers of cached resources in network panel.

Source/devtools/front_end/network/RequestHeadersView.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) IBM Corp. 2009  All rights reserved.
  * 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 358 matching lines @@
 
         if (headersText) {
             var toggleButton = this._createHeadersToggleButton(this._showResponseHeadersText);
             toggleButton.addEventListener("click", this._toggleResponseHeadersText.bind(this), false);
             treeElement.listItemElement.appendChild(toggleButton);
         }
     },
 
     _refreshHTTPInformation: function()
     {
+        this.element.classList.toggle("cached", this._request.cached);
+
         var requestMethodElement = this._requestMethodTreeElement;
         requestMethodElement.hidden = !this._request.statusCode;
         var statusCodeElement = this._statusCodeTreeElement;
         statusCodeElement.hidden = !this._request.statusCode;
 
         if (this._request.statusCode) {
             var statusCodeFragment = document.createDocumentFragment();
             statusCodeFragment.createChild("div", "header-name").textContent = WebInspector.UIString("Status Code") + ":";
 
             var statusCodeImage = statusCodeFragment.createChild("div", "resource-status-image");
@@ skipping 28 matching lines @@
         headersTreeElement.listItemElement.createTextChild(title);
 
         var headerCount = WebInspector.UIString(" (%d)", headersLength);
         headersTreeElement.listItemElement.createChild("span", "header-count").textContent = headerCount;
     },
 
     /**
      * @param {string} title
      * @param {!Array.<!WebInspector.NetworkRequest.NameValue>} headers
      * @param {!TreeElement} headersTreeElement
-     * @param {boolean=} showCaution
+     * @param {boolean=} provisionalHeaders
      */
-    _refreshHeaders: function(title, headers, headersTreeElement, showCaution)
+    _refreshHeaders: function(title, headers, headersTreeElement, provisionalHeaders)
     {
         headersTreeElement.removeChildren();
 
         var length = headers.length;
         this._refreshHeadersTitle(title, headersTreeElement, length);
 
+        var showCaution = provisionalHeaders && !this._request.cached;
+
         if (showCaution) {
             var cautionText = WebInspector.UIString("Provisional headers are shown");
             var cautionFragment = document.createDocumentFragment();
             cautionFragment.createChild("div", "warning-icon-small");
             cautionFragment.createChild("div", "caution").textContent = cautionText;
             var cautionTreeElement = new TreeElement(cautionFragment);
             cautionTreeElement.selectable = false;
             headersTreeElement.appendChild(cautionTreeElement);
         }
 
@@ skipping 61 matching lines @@
      * @return {!Element}
      */
     _createHeadersToggleButton: function(isHeadersTextShown)
     {
         var toggleTitle = isHeadersTextShown ? WebInspector.UIString("view parsed") : WebInspector.UIString("view source");
         return this._createToggleButton(toggleTitle);
     },
 
     __proto__: WebInspector.VBox.prototype
 }