DevTools: implement hidpi-friendly success/error/warning balls.

Source/devtools/front_end/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 356 matching lines @@
     },
 
     _refreshHTTPInformation: function()
     {
         var requestMethodElement = this._requestMethodTreeElement;
         requestMethodElement.hidden = !this._request.statusCode;
         var statusCodeElement = this._statusCodeTreeElement;
         statusCodeElement.hidden = !this._request.statusCode;
 
         if (this._request.statusCode) {
-            var statusImageSource = "";
+            var statusCodeFragment = document.createDocumentFragment();
+            statusCodeFragment.createChild("div", "header-name").textContent = WebInspector.UIString("Status Code") + ":";
+
+            var statusCodeImage = statusCodeFragment.createChild("div", "resource-status-image");
+            statusCodeImage.title = this._request.statusCode + " " + this._request.statusText;
+
             if (this._request.statusCode < 300 || this._request.statusCode === 304)
-                statusImageSource = "Images/successGreenDot.png";
+                statusCodeImage.addStyleClass("green-ball");
             else if (this._request.statusCode < 400)
-                statusImageSource = "Images/warningOrangeDot.png";
+                statusCodeImage.addStyleClass("orange-ball");
             else
-                statusImageSource = "Images/errorRedDot.png";
+                statusCodeImage.addStyleClass("red-ball");
 
             requestMethodElement.title = this._formatHeader(WebInspector.UIString("Request Method"), this._request.requestMethod);
 
-            var statusCodeFragment = document.createDocumentFragment();
-            statusCodeFragment.createChild("div", "header-name").textContent = WebInspector.UIString("Status Code") + ":";
-
-            var statusCodeImage = statusCodeFragment.createChild("img", "resource-status-image");
-            statusCodeImage.src = statusImageSource;
-            statusCodeImage.title = this._request.statusCode + " " + this._request.statusText;
             var value = statusCodeFragment.createChild("div", "header-value source-code");
             value.textContent = this._request.statusCode + " " + this._request.statusText;
             if (this._request.cached)
                 value.createChild("span", "status-from-cache").textContent = " " + WebInspector.UIString("(from cache)");
 
             statusCodeElement.title = statusCodeFragment;
         }
     },
 
     _refreshHeadersTitle: function(title, headersTreeElement, headersLength)
@@ skipping 49 matching lines @@
     },
 
     _createHeadersToggleButton: function(isHeadersTextShown)
     {
         var toggleTitle = isHeadersTextShown ? WebInspector.UIString("view parsed") : WebInspector.UIString("view source");
         return this._createToggleButton(toggleTitle);
     },
 
     __proto__: WebInspector.View.prototype
 }