GitLab

Move tough_pinch_zoom_cases into the rendering folder and refactor to
inherit from RenderingStory

Bug: 849392
Change-Id: I6496aacc50aa730843d677e73c89f3025b0799ba
Reviewed-on: https://chromium-review.googlesource.com/1087726
Commit-Queue: Amy Qiu <amyqiu@google.com>
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#564941}