[iOS][web] Merge CRWWebController methods

This CL merge the -setWebView: method to its readonly property.
It moves loadHTML: close to its public declaration as it is only here
for testing purpose.
It also remove +webControllerCanShow, putting its code in its call
site.

Bug: 938255
Change-Id: If8970a58a5eb99b8be5e67eb1006b088d0dd05d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1505444
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638528}
1 file changed