GitLab

This CL upgrades cr-lazy-render for compatibility with Polymer 2. It
does this by using a slot for a <template> from the light DOM which
gets templatized since the cr-lazy-render element itself can no longer
be a <template>.

This means that all clients need to wrap their light DOM in <template>
tags.

Bug: 818279
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Ieaed7cb2f9422557aed0c3a388939b17b5825245
Reviewed-on: https://chromium-review.googlesource.com/977203
Commit-Queue: calamity <calamity@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546012}