contacts: Add ContactManager.

chrome/browser/chromeos/contacts/google_contact_store.cc

Index: chrome/browser/chromeos/contacts/google_contact_store.cc
diff --git a/chrome/browser/chromeos/contacts/google_contact_store.cc b/chrome/browser/chromeos/contacts/google_contact_store.cc
index b80961836adee00eddf5f35545c1e07da52758ec..551d0af99179d94e2a47a5d7c5334bfdc1463980 100644
--- a/chrome/browser/chromeos/contacts/google_contact_store.cc
+++ b/chrome/browser/chromeos/contacts/google_contact_store.cc
@@ -85,8 +85,7 @@ GoogleContactStore::GoogleContactStore(Profile* profile)
 }
 
 GoogleContactStore::~GoogleContactStore() {
-  // This should also be running on the UI thread but we can't check it; the
-  // message loop is typically already getting torn down at this point.
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   weak_ptr_factory_.InvalidateWeakPtrs();
   DestroyDatabase();
 }