Resubmit 'Enable the volume slider in Windows Ash'.

Previous 2 submissions were causing the Vista waterfall builder to fail
with uninitialized COM errors.  This change addresses that by
initializing COM on Vista+, not just Win7+.

TBRing all reviewers since this change has already been reviewed.

BUG=227247
TEST=Ran ash_unittests on a Vista VM
     * All tests failed without my change.
     * All tests passed with my change.
TBR=henrika,sky,jennyz

Review URL: https://codereview.chromium.org/197643003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256608 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ash/test/test_suite.cc b/ash/test/test_suite.cc
index 2e971eb7..79552647 100644
--- a/ash/test/test_suite.cc
+++ b/ash/test/test_suite.cc
@@ -33,12 +33,16 @@
   gfx::GLSurface::InitializeOneOffForTests();
 
 #if defined(OS_WIN)
-  if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
+  base::win::Version version = base::win::GetVersion();
+  // Although Ash officially is only supported for users on Win7+, we still run
+  // ash_unittests on Vista builders, so we still need to initialize COM.
+  if (version >= base::win::VERSION_VISTA &&
       !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