unified-heap: Provide names for internal classes in heap snapshot

Provide a name for internal nodes in non-production builds.

This is very useful for manual debugging builds but may confuse people
without providing better DevTools integration.

Bug: 843903
Change-Id: Ifd7359575beb3c916a86fc6091abfc20c76e6b64
Reviewed-on: https://chromium-review.googlesource.com/c/1412472
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623177}
5 files changed