Remove unused source code in PPAPI

Bug: 40511450
Change-Id: Id469003594da402cb4cdb3e83f257830dc9e353c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6696273
Reviewed-by: Derek Schuff <[email protected]>
Commit-Queue: Eugene Zemtsov <[email protected]>
Reviewed-by: Tom Sepez <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1481245}
NOKEYCHECK=True
GitOrigin-RevId: b54fb3d12a612c8cba47c8928f52ae873da1071f
982 files changed