Since the gn builders do not resolve the DEPS after patch, the patch cannot contain
both the DEPS change as well the usage of the newly added DEPS.

If the CL mentioned in the title does not land, this CL is to be remove/reverted as well.

BUG=v8:4560
LOG=N

Review URL: https://codereview.chromium.org/1469303004

Cr-Commit-Position: refs/heads/master@{#32296}