Only do aggressive metro viewer termination in tests

ash/test/ash_test_base.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/ash_test_base.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/ash_switches.h"
@@ skipping 158 matching lines @@
           ash::switches::kForceAshToDesktop)) {
     // Check that our viewer connection is still established.
     CHECK(!metro_viewer_host_->closed_unexpectedly());
   }
 #endif
 
   ash_test_helper_->TearDown();
 #if defined(OS_WIN)
   ui::test::SetUsePopupAsRootWindowForTest(false);
   // Kill the viewer process if we spun one up.
+  metro_viewer_host_->TerminateViewer();
   metro_viewer_host_.reset();
-
-  // Clean up any dangling viewer processes as the metro APIs sometimes leave
-  // zombies behind. A default browser process in metro will have the
-  // following command line arg so use that to avoid killing all processes named
-  // win8::test::kDefaultTestExePath.
-  const wchar_t kViewerProcessArgument[] = L"DefaultBrowserServer";
-  base::KillAllNamedProcessesWithArgument(win8::test::kDefaultTestExePath,
-                                          kViewerProcessArgument);
 #endif
 
   event_generator_.reset();
   // Some tests set an internal display id,
   // reset it here, so other tests will continue in a clean environment.
   gfx::Display::SetInternalDisplayId(gfx::Display::kInvalidDisplayID);
 }
 
 ui::test::EventGenerator& AshTestBase::GetEventGenerator() {
   if (!event_generator_) {
@@ skipping 138 matching lines @@
 
 void AshTestBase::UnblockUserSession() {
   Shell::GetInstance()->session_state_delegate()->UnlockScreen();
   SetSessionStarted(true);
   SetUserAddingScreenRunning(false);
 }
 
 
 }  // namespace test
 }  // namespace ash