[tools/perf] Add CodeAndMetadata metrics to v8_browsing benchmarks and add Ignition variants

Adds CodeAndMetadata measurements to the v8_browsing telemetry benchmarks.
Modifes the memory dumper to dump these stats on light dumps, if requested.
Also adds an Ignition variant for v8_browsing benchmarks.

BUG=v8:4280,v8:5019
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.perf:android_s5_perf_cq;master.tryserver.chromium.perf:linux_perf_cq;master.tryserver.chromium.perf:mac_retina_perf_cq;

Review-Url: https://codereview.chromium.org/2257173003
Cr-Commit-Position: refs/heads/master@{#414439}
2 files changed