Refactor FindForwardBoxInPossiblyBidiContext for SelectionModifierCharacter

The above mentioned function currently mutates its local variables
arbitrarily, making the code hard to read.

This patch changes all local variables to constants to improve readability.

Change-Id: Ica7c155633cf3091ad4ed53f98baca5842f93ea6
Reviewed-on: https://chromium-review.googlesource.com/1068150
Reviewed-by: Yoichi Osato <yoichio@chromium.org>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560498}
1 file changed