This is preparing for gclient switching.
Build break is expected. Some change in build script is required.
Change-Id: I4ebb78d3ae3114318c101ff4927954c89fce9a1d
Some of the modules was semi-setup when copied from chromium.
With submodule setup, the user may use git submodule init and update
to update the submodules.
Change-Id: Ief0899c1567cd2be9a55710f7f81c0eb74461f50