RFR: 8259956: jdk.jfr.internal.ChunkInputStream#available should return the sum of remaining available bytes [v7]

[Denghui Dong]

> Could I have a review of this small fix?
> 
> In the current implementation, ChunkInputStream#available only returns the available size of the current stream, which is strange for the user.

Denghui Dong has updated the pull request incrementally with one additional commit since the last revision:

  improve test

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2138/files
  - new: https://git.openjdk.java.net/jdk/pull/2138/files/af34d74d..612ee6cd

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2138&range=06
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2138&range=05-06

  Stats: 31 lines in 1 file changed: 1 ins; 19 del; 11 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2138.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2138/head:pull/2138

PR: https://git.openjdk.java.net/jdk/pull/2138