tree a04ad3b06f0e5acfded30cb2731367f0cefefe25
parent fbea0a63130cb800c39b15b315e469477ae4a5ef
author Ryan Macnak <rmacnak@google.com> 1542326408 -0800
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1542764500 +0000

[dart] Support creating a multi-root overlay in compiler.dart.

Test: build
Change-Id: Iae610274ed2d1bd6a1e3adf3d9d33d175c5d10a6