Disallow mixing of Canadian Syllabary and [a-z]

Merging to 3071 (M59) branch.

BUG=719199
TEST=components_unittests --gtest_filter=*IDNToUn*
TBR=jshin@chromium.org

(cherry picked from commit e2fde40094b4c9b56a7e6342ab1c8bbe75381761)

Review-Url: https://codereview.chromium.org/2871643005
Cr-Original-Commit-Position: refs/heads/master@{#471538}
Change-Id: Ib5b7055b8ecf831e11be79dbe75f2738f4d527e6
Reviewed-on: https://chromium-review.googlesource.com/517223
Reviewed-by: Jungshik Shin <jshin@chromium.org>
Cr-Commit-Position: refs/branch-heads/3071@{#702}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
2 files changed