GitLab

Convert usage of GTMStringEncoding that were used to convert
to/from base64 (possibly the web safe variant) to use //base
instead (which provides an encoder/decoder).

Remove dependencies on //third_party/google_toolbox_for_mac
from //ios/chrome that are no longer used (i.e. the code do
not use GTM and the include are stale).

Removing those dependencies may enable Chrome on iOS to drop
the dependency on //third_party/google_toolbox_for_mac.

Bug: none
Tbr: rsesek@chromium.org
Change-Id: I82939c005c762a9914ece809ec3e7767ed8db729
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1899458
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: David Jean <djean@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712595}