Introduce a tab bar

This will make it easier to add a third tab to HtmlReporterV2.

src/html/requireHtml.js

@@ -11,6 +11,7 @@ jasmineRequire.html = function(j$) {
   j$.private.SymbolsView = jasmineRequire.SymbolsView(j$);
   j$.private.SummaryTreeView = jasmineRequire.SummaryTreeView(j$);
   j$.private.FailuresView = jasmineRequire.FailuresView(j$);
+  j$.private.TabBar = jasmineRequire.TabBar(j$);
   j$.HtmlReporter = jasmineRequire.HtmlReporter(j$);
   j$.HtmlReporterV2Urls = jasmineRequire.HtmlReporterV2Urls(j$);
   j$.HtmlReporterV2 = jasmineRequire.HtmlReporterV2(j$);