Enable the volume slider in Ash for windows.

ash/test/test_suite.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/test/test_suite.h"
 
 #include "ash/ash_switches.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/path_service.h"
@@ skipping 15 matching lines @@
 namespace test {
 
 AuraShellTestSuite::AuraShellTestSuite(int argc, char** argv)
     : TestSuite(argc, argv) {}
 
 void AuraShellTestSuite::Initialize() {
   base::TestSuite::Initialize();
   gfx::GLSurface::InitializeOneOffForTests(true);
 
 #if defined(OS_WIN)
-  if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
+  base::win::Version version = base::win::GetVersion();
+  if (version >= base::win::VERSION_WIN7 &&
       !CommandLine::ForCurrentProcess()->HasSwitch(
           ash::switches::kForceAshToDesktop)) {
     com_initializer_.reset(new base::win::ScopedCOMInitializer());
     ui::win::CreateATLModuleIfNeeded();
-    ASSERT_TRUE(win8::MakeTestDefaultBrowserSynchronously());
+    if (version >= base::win::VERSION_WIN8)
+      ASSERT_TRUE(win8::MakeTestDefaultBrowserSynchronously());
   }
 #endif
 
   gfx::RegisterPathProvider();
   ui::RegisterPathProvider();
 
   // Force unittests to run using en-US so if we test against string
   // output, it'll pass regardless of the system language.
   ui::ResourceBundle::InitSharedInstanceWithLocale("en-US", NULL);
 }
 
 void AuraShellTestSuite::Shutdown() {
   ui::ResourceBundle::CleanupSharedInstance();
 #if defined(OS_WIN)
   com_initializer_.reset();
 #endif
   base::TestSuite::Shutdown();
 }
 
 }  // namespace test
 }  // namespace ash