Update trans limit after zoom changes in viewer

Previously, the trans limit assumes that only touch gesture can
change the zoom level. That's not true on desktops so we need this
fix. Otherwise, we won't be able to translate when we zoomed in.

Bug: skia:
Change-Id: I5901600a0044639a47514ab76b7e1914f04137a2
Reviewed-on: https://skia-review.googlesource.com/116987
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Yuqian Li <liyuqian@google.com>
2 files changed