RFR: 8367578: Additional WebKit 622.1 fixes from WebKitGTK 2.48.7 [v2]

[Jay Bhaskar]

> WebKitGTK 2.48.6 and 2.48.7 are bug-fix releases that improve stability, fix crashes, memory leaks, emoji rendering, WebP animation stuttering, and CSS animation issues, while also adding better font support and preventing unnecessary memory monitoring.

Jay Bhaskar has updated the pull request incrementally with one additional commit since the last revision:

  adding review comments

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1933/files
  - new: https://git.openjdk.org/jfx/pull/1933/files/c54d91fa..c6edc7bf

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1933&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1933&range=00-01

  Stats: 8 lines in 2 files changed: 1 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jfx/pull/1933.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1933/head:pull/1933

PR: https://git.openjdk.org/jfx/pull/1933