This makes the isolate-driver script rebase all paths to be
relative to the isolate-file location. This is an assumption
of the go binaries and is needed for batcharchive to work.
In gyp, actions were executed relative to the gyp file that
specified them, while in gn it's relative to the product dir.
BUG=chromium:474921
Review-Url: https://codereview.chromium.org/2039873002
Cr-Commit-Position: refs/heads/master@{#36746}
This is a simplified version of chromium's isolate driver:
- 'prepare' will create a *.isolate.gen.json with the
arguments to be used later.
- other modes will just be passed through to the isolate
script.
BUG=chromium:535160
LOG=n
NOTRY=true
Review URL: https://codereview.chromium.org/1378133005
Cr-Commit-Position: refs/heads/master@{#31046}
