Introduce a single call to grab default browser on Win8 for tests.

ash/test/test_suite.cc

Index: ash/test/test_suite.cc
diff --git a/ash/test/test_suite.cc b/ash/test/test_suite.cc
index 458aaebcba889dd2488f73e76bc2e8d52a03b61a..9b51ad07b829946a4df36eab2b3b89bcafd32f1f 100644
--- a/ash/test/test_suite.cc
+++ b/ash/test/test_suite.cc
@@ -21,10 +21,9 @@
 #endif
 
 #if defined(OS_WIN)
+#include "base/win/scoped_com_initializer.h"
 #include "base/win/windows_version.h"
-#include "ui/base/win/atl_module.h"
 #include "win8/test/metro_registration_helper.h"
-#include "win8/test/open_with_dialog_controller.h"
 #include "win8/test/test_registrar_constants.h"
 #endif
 
@@ -41,16 +40,8 @@ void AuraShellTestSuite::Initialize() {
   if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
       !CommandLine::ForCurrentProcess()->HasSwitch(
           ash::switches::kForceAshToDesktop)) {
-    ASSERT_TRUE(win8::RegisterTestDefaultBrowser(
-        win8::test::kDefaultTestAppUserModelId,
-        win8::test::kDefaultTestExeName));
-
-    ui::win::CreateATLModuleIfNeeded();
-
-    std::vector<base::string16> choices;
-    win8::OpenWithDialogController controller;
-    controller.RunSynchronously(NULL, L"http", win8::test::kDefaultTestExeName,
-                                &choices);
+    base::win::ScopedCOMInitializer com_initializer;

[grt (UTC plus 2), 2013/05/27 16:11:14]

COM shouldn't be initialized and uninitialized like this (see
http://crbug.com/145095 for reference). initialize it once on the thread and
only tear it down at exit.

[gab, 2013/05/27 16:47:58]

I see, moved it as a member of AuraShellTestSuite (and made sure this didn't
result in double COM initialization errors).

+    ASSERT_TRUE(win8::MakeTestDefaultBrowserSynchronously());
   }
 #endif