Convert ImageReviewableView and RegionCommentBlockView to ES6.

Review Request #8214 — Created June 3, 2016 and submitted — Latest diff uploaded

Information

Review Board
release-3.0.x
870eca9...

Reviewers

This change does the basic conversion (let/const, member function sugar, fix up
and add documentation comments), but also consolidates the code a bit to remove
extra helper functions that were only called from one place and didn't help
structure the code any better.

This is in preparation for the high-DPI image review feature.

  • Ran unit tests.
  • Used in conjunction with other changes.