bug 1203861 - use strncmp() instead of nsCString.equals() to compare names r=davidb

AtkObject stores the name as a C string, but nsCString can store strings with
'\0' in the middle.  That means that if we compute a name containing '\0'
nsCString.equals() will nevr consider that string to be equal to
AtkObject::name, however we only want to compare up to the first '\0' because
that is the only part Atk will ever see.  So we should use strncmp() instead of
nsCString.equals().

accessible/atk/AccessibleWrap.cpp

@@ -597,7 +597,8 @@ static void
 MaybeFireNameChange(AtkObject* aAtkObj, const nsString& aNewName)
 {
   NS_ConvertUTF16toUTF8 newNameUTF8(aNewName);
-  if (aAtkObj->name && newNameUTF8.Equals(aAtkObj->name))
+  if (aAtkObj->name &&
+      !strncmp(aAtkObj->name, newNameUTF8.get(), newNameUTF8.Length()))
     return;
 
   // Below we duplicate the functionality of atk_object_set_name(),