Fix errors in MB when run for the first time on a new builder.
commitc3441d156f8beb8cdd76880988132c197ddef2e1
authordpranke <dpranke@chromium.org>
Tue, 23 Jun 2015 23:01:35 +0000 (23 16:01 -0700)
committerCommit bot <commit-bot@chromium.org>
Tue, 23 Jun 2015 23:02:23 +0000 (23 23:02 +0000)
treef0a452feaf9e4fe6639c7767070eb8d76c07927c
parent9284be15c90de0ec53f6112ca530893292037674
Fix errors in MB when run for the first time on a new builder.

The first time we run a build on a GN builder, it's possible
that MB will run and the build directory (//out/Release) may not
exist yet; in that case, we need to create the directory before
trying to write the list of runtime_deps that GN will need to read.

R=maruel@chromium.org
BUG=480053

Review URL: https://codereview.chromium.org/1204793002

Cr-Commit-Position: refs/heads/master@{#335793}
tools/mb/mb.py
tools/mb/mb_unittest.py