Update third_party/wuffs to version 0.2.0-rc.3

Bug: 1014044
Change-Id: I6361907375c981a567e12c95262bbd02d55c31f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1895260
Commit-Queue: Leon Scroggins <scroggo@chromium.org>
Reviewed-by: Leon Scroggins <scroggo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712129}

DEPS

@@ -323,7 +323,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling wuffs
   # and whatever else without interference from each other.
-  'wuffs_revision': '4080840928c0b05a80cda0d14ac2e2615f679f1a',
+  'wuffs_revision': '7ec252876541ec203659949450fafddc148b606e',
 
   # TODO(crbug.com/941824): The values below need to be kept in sync
   # between //DEPS and //buildtools/DEPS, so if you're updating one,