[GN] Add a few more unit tests for Xcode objects.

This CL adds unit test files for Xcode objects in
tools/gn/xcode_object.h, and specifically tests the mapping between
a object and its class enum type and the mapping between a classe type 
and its name as a string.

Bug: 742258
Change-Id: Iab70bc2f3c0eedccd427e618d74f8077dcaee5c7
Reviewed-on: https://chromium-review.googlesource.com/630699
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#497064}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: da4fc47d51d4aa4da88816fb33b255be01d95885
1 file changed
tree: abccc5c1a75e577f73b4e90027bd7c740df7622d
  1. tools/