DevTools: Support multiple simulateneous sampling heap profiles.
DevTools: Support multiple simulateneous sampling heap profiles.

BUG=937880

Change-Id: Iba9c70b2c3420670ab596bbae9cb825a6c3496b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1552407
Reviewed-by: Pavel Feldman <e1161d7019a0d5c7981e3c3ffc69c76f4b09679a@chromium.org>
Commit-Queue: Alexei Filippov <52e51c43e283548b762e3c9dd9a4600768db9fb4@chromium.org>
Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#647884}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 492a0202249a8ba6e71c49bf45ac6e9900d20e40
ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend