GitLab

Update Polymer Bundler and Polymer CSS build to more recent versions,
and adjust as necessary to fix build and test breakages from the
bundler update. This is a prerequisite for updating bundled Web UI
pages to use JS modules/Polymer 3.

This update increases the size of npm_modules.tar.gz by around 18%
(1M), because we need to support both Polymer2 and Polymer3 in the
toolchain during the migration. Once Polymer2 related tools
(polymer-bundler, crisper) are removed, npm_modules.tar.gz's size
will be decreased again by a similar amount.

Some fixes for bundler v4.0.10 originally from:
https://chromium-review.googlesource.com/c/chromium/src/+/1652566
by aee@.

Bug: 921285
Change-Id: Ibb751cdac789af70e87f3774c5d27d0cafd57150
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1857568
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707619}