mac: remove libc++-static 10.6 compatibility hack

third_party/libc++-static/README.chromium

Index: third_party/libc++-static/README.chromium
diff --git a/third_party/libc++-static/README.chromium b/third_party/libc++-static/README.chromium
deleted file mode 100644
index fa767ce12d9695e81ce333065e06fd4dfb0f69c4..0000000000000000000000000000000000000000
--- a/third_party/libc++-static/README.chromium
+++ /dev/null
@@ -1,29 +0,0 @@
-Name: libcxx
-Short Name: libc++
-Security Critical: Yes
-License: MIT
-License File: LICENSE.TXT
-Version: 0
-Revision: 245965
-URL: http://libcxx.llvm.org/
-
-To upload (run automatically by build.sh):
-  upload_to_google_storage.py -b chromium-libcpp third_party/libc++-static/libc++.a
-
-To initialize gsutil's credentials:
-  python ~/depot_tools/third_party/gsutil/gsutil config
-
-  That will give a URL which you should log into with your web browser. The
-  username should be the one that is on the ACL for the "chromium-libcpp"
-  bucket (probably your @google.com address). Contact the build team for help
-  getting access if necessary.
-
-  Copy the code back to the command line util. Ignore the project ID (it's OK
-  to just leave blank when prompted).
-
-gsutil documentation:
-  https://developers.google.com/storage/docs/gsutil
-
-
-To build: Run `third_party/libc++-static/build.sh`.  It'll upload to google
-storage and update the .sha1 file.