GitLab

Adds better output for EXPECT/DCHECK/ASSERT around common layout types
including SizeBounds, as well as providing ToString() methods for
ProposedLayout and ChildLayout used by all LayoutManagerBase-derived
layout managers.

Change-Id: If9c5c99ac3aec2db4969038739fea6118e893191
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1958695
Commit-Queue: Dana Fried <dfried@chromium.org>
Reviewed-by: Peter Boström <pbos@chromium.org>
Auto-Submit: Dana Fried <dfried@chromium.org>
Cr-Commit-Position: refs/heads/master@{#723657}