RFR: 6542: Improve calls to render in the flame view [v23]

[Miroslav Wengner]

> stable flameview generation

Miroslav Wengner has updated the pull request incrementally with one additional commit since the last revision:

  6542: check future cancelation

-------------

Changes:
  - all: https://git.openjdk.java.net/jmc/pull/78/files
  - new: https://git.openjdk.java.net/jmc/pull/78/files/11e29db3..0a976b5b

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jmc&pr=78&range=22
 - incr: https://webrevs.openjdk.java.net/?repo=jmc&pr=78&range=21-22

  Stats: 13 lines in 1 file changed: 8 ins; 0 del; 5 mod
  Patch: https://git.openjdk.java.net/jmc/pull/78.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/78/head:pull/78

PR: https://git.openjdk.java.net/jmc/pull/78