DevTools: use target-based model accessors only.

LayoutTests/http/tests/inspector/resources-test.js

 var initialize_ResourceTest = function() {
 
 InspectorTest.preloadPanel("resources");
 
 InspectorTest.requestURLComparer = function(r1, r2)
 {
     return r1.request.url.localeCompare(r2.request.url);
 }
 
 InspectorTest.runAfterCachedResourcesProcessed = function(callback)
 {
-    if (!WebInspector.resourceTreeModel._cachedResourcesProcessed)
-        WebInspector.resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.CachedResourcesLoaded, callback);
+    if (!InspectorTest.resourceTreeModel._cachedResourcesProcessed)
+        InspectorTest.resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.CachedResourcesLoaded, callback);
     else
         callback();
 }
 
 InspectorTest.runAfterResourcesAreFinished = function(resourceURLs, callback)
 {
     var resourceURLsMap = resourceURLs.keySet();
 
     function checkResources()
     {
         for (url in resourceURLsMap) {
             var resource = InspectorTest.resourceMatchingURL(url);
             if (resource)
                 delete resourceURLsMap[url];
         }
         if (!Object.keys(resourceURLsMap).length) {
-            WebInspector.resourceTreeModel.removeEventListener(WebInspector.ResourceTreeModel.EventTypes.ResourceAdded, checkResources);
+            InspectorTest.resourceTreeModel.removeEventListener(WebInspector.ResourceTreeModel.EventTypes.ResourceAdded, checkResources);
             callback();
         }
     }
     checkResources();
     if (Object.keys(resourceURLsMap).length)
-        WebInspector.resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.ResourceAdded, checkResources);
+        InspectorTest.resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.ResourceAdded, checkResources);
 }
 
 InspectorTest.showResource = function(resourceURL, callback)
 {
     var reported = false;
     function callbackWrapper(sourceFrame)
     {
         if (reported)
             return;
         callback(sourceFrame);
@@ skipping 11 matching lines @@
             callbackWrapper(sourceFrame);
         else
             InspectorTest.addSniffer(sourceFrame, "onTextEditorContentLoaded", callbackWrapper.bind(null, sourceFrame));
     }
     InspectorTest.runAfterResourcesAreFinished([resourceURL], showResourceCallback);
 }
 
 InspectorTest.resourceMatchingURL = function(resourceURL)
 {
     var result = null;
-    WebInspector.resourceTreeModel.forAllResources(visit);
+    InspectorTest.resourceTreeModel.forAllResources(visit);
     function visit(resource)
     {
         if (resource.url.indexOf(resourceURL) !== -1) {
             result = resource;
             return true;
         }
     }
     return result;
 }
 
 }