Merge tools/gyp from https://chromium.googlesource.com/external/gyp.git at b38e5f2f93fa5b31a6001bd21b9d8dcbf73e44e7

This commit was generated by merge_from_chromium.py.

Change-Id: Ide8ea95cde4d50b827c99556bef533b85232e6b9