All submodule pointers are now private. The unique_ptr to a ApmPrivateSubmodules is replaced by a direct member object. The main outcome of this CL is that the code is nicer. Bug: webrtc:5298 Change-Id: Ib8ef70a35a64b875752d2a318c572d152d51487a Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/157440 Reviewed-by: Per Åhgren <peah@webrtc.org> Commit-Queue: Sam Zackrisson <saza@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29539}