Make policy removable using ifdefs instead of stubs.

For the gyp flag configuration_policy=0, use ifdefs in the places where
policy classes are referred to, rather than providing stubs that
implement parts of the policy classes. This is somewhat simpler and less
fragile. This reverts part of r87468 (where this flag was introduced)
but keeps other parts which are still valuable.

BUG=85534

Review URL: http://codereview.chromium.org/7343008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@92549 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 9863addf..3c78aef 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -113,7 +113,9 @@
   BackgroundModeManager::RegisterPrefs(local_state);
   NotificationUIManager::RegisterPrefs(local_state);
   PrefProxyConfigService::RegisterPrefs(local_state);
+#if defined(ENABLE_CONFIGURATION_POLICY)
   policy::CloudPolicySubsystem::RegisterPrefs(local_state);
+#endif
   ProfileInfoCache::RegisterPrefs(local_state);
   ProfileManager::RegisterPrefs(local_state);
 #if defined(OS_CHROMEOS)