contacts: Rename provider_id to contact_id.

chrome/browser/chromeos/contacts/contact_manager.h

Index: chrome/browser/chromeos/contacts/contact_manager.h
diff --git a/chrome/browser/chromeos/contacts/contact_manager.h b/chrome/browser/chromeos/contacts/contact_manager.h
index c5fa4e0b923ff8f1430f926c557cae4bc43a3fa8..b729df4afcdd4022511c0ff6f7c33a47be2691bf 100644
--- a/chrome/browser/chromeos/contacts/contact_manager.h
+++ b/chrome/browser/chromeos/contacts/contact_manager.h
@@ -52,10 +52,10 @@ class ContactManager : public ContactStoreObserver,
   // refer to them again after unblocking the UI thread.
   scoped_ptr<ContactPointers> GetAllContacts(Profile* profile);
 
-  // Returns the contact identified by |provider_id|.
+  // Returns the contact identified by |contact_id|.
   // NULL is returned if the contact doesn't exist.
-  const Contact* GetContactByProviderId(Profile* profile,
-                                        const std::string& provider_id);
+  const Contact* GetContactById(Profile* profile,
+                                const std::string& contact_id);
 
   // ContactStoreObserver overrides:
   virtual void OnContactsUpdated(ContactStore* store) OVERRIDE;