DevTools: add console test helpers to new test runner & migrate a console test

third_party/WebKit/LayoutTests/http/tests/inspector/console-test.js

 var initialize_ConsoleTest = function() {
 
 InspectorTest.preloadModule("source_frame");
 InspectorTest.preloadPanel("console");
 
 InspectorTest.selectMainExecutionContext = function()
 {
     var executionContexts = InspectorTest.runtimeModel.executionContexts();
     for (var context of executionContexts) {
         if (context.isDefault) {
@@ skipping 217 matching lines @@
 
 InspectorTest.dumpConsoleClassesBrief = function()
 {
     var messageViews = Console.ConsoleView.instance()._visibleViewMessages;
     for (var i = 0; i < messageViews.length; ++i)
         InspectorTest.addResult(messageViews[i].toMessageElement().className);
 }
 
 InspectorTest.dumpConsoleCounters = function()
 {
-    var counter = Main.Main.WarningErrorCounter._instanceForTest;
+    var counter = Counters.WarningErrorCounter._instanceForTest;
     for (var index = 0; index < counter._titles.length; ++index)
         InspectorTest.addResult(counter._titles[index]);
     InspectorTest.dumpConsoleClassesBrief();
 }
 
 InspectorTest.expandConsoleMessages = function(callback, deepFilter, sectionFilter)
 {
     Console.ConsoleView.instance()._invalidateViewport();
     var messageViews = Console.ConsoleView.instance()._visibleViewMessages;
 
@@ skipping 192 matching lines @@
                     offset: offset - charCount
                 };
             }
             charCount += length;
         }
         return null;
     }
 }
 
 }