GitLab

Plumb custom bounds through DstRangeRelationToSrcRange to remove
duplicate comparisons. Refactor RangeConstraint from an enum to a class
containing bools, which can be independently evaluated at compile-time.

NOTRY=true

Review-Url: https://codereview.chromium.org/2585043002
Cr-Commit-Position: refs/heads/master@{#439508}