Add TestBrowserThreadBundle into RenderViewHostTestHarness. Kill some unnecessary real threads.

chrome/browser/web_applications/web_app_unittest.cc

Index: chrome/browser/web_applications/web_app_unittest.cc
diff --git a/chrome/browser/web_applications/web_app_unittest.cc b/chrome/browser/web_applications/web_app_unittest.cc
index 149f62b9b73c6a98952016e5856c5473cbf76e39..a8a760cf2e22d430e868b17a77bb4dc94572b423 100644
--- a/chrome/browser/web_applications/web_app_unittest.cc
+++ b/chrome/browser/web_applications/web_app_unittest.cc
@@ -12,26 +12,18 @@
 #include "chrome/browser/ui/web_applications/web_app_ui.h"
 #include "chrome/common/extensions/extension_messages.h"
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
-#include "content/public/test/test_browser_thread.h"
 #include "content/public/test/test_renderer_host.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-using content::BrowserThread;
 using content::RenderViewHostTester;
 
 class WebApplicationTest : public ChromeRenderViewHostTestHarness {
- public:
-  WebApplicationTest() : ui_thread_(BrowserThread::UI, &message_loop_) {
-  }
-
- private:
+ protected:
   virtual void SetUp() OVERRIDE {
     ChromeRenderViewHostTestHarness::SetUp();
     extensions::TabHelper::CreateForWebContents(web_contents());
     FaviconTabHelper::CreateForWebContents(web_contents());
   }
-
-  content::TestBrowserThread ui_thread_;
 };
 
 #if defined(OS_MACOSX)