DevTools: use timing information for "disk cached" resources.

Source/devtools/front_end/network/RequestHeadersView.js

Index: Source/devtools/front_end/network/RequestHeadersView.js
diff --git a/Source/devtools/front_end/network/RequestHeadersView.js b/Source/devtools/front_end/network/RequestHeadersView.js
index 47eb3d14578ff5ce21bfe1a032dd649ef7ccddeb..eabd0056b8415c5a046ff152d511dc7dd3d57c8a 100644
--- a/Source/devtools/front_end/network/RequestHeadersView.js
+++ b/Source/devtools/front_end/network/RequestHeadersView.js
@@ -402,7 +402,7 @@ WebInspector.RequestHeadersView.prototype = {
             if (this._request.fetchedViaServiceWorker) {
                 statusText += " " + WebInspector.UIString("(from ServiceWorker)");
                 statusTextElement.classList.add("status-from-cache");
-            } else if (this._request.cached) {
+            } else if (this._request.cached()) {
                 statusText += " " + WebInspector.UIString("(from cache)");
                 statusTextElement.classList.add("status-from-cache");
             }