Convert make_unique<ExpressionStatement> to ExpressionStatement::Make.

This allows for elimination expression-statements with no side effects
when they are first created, rather than later on in the control-flow
optimization pass.

Change-Id: I09ec8421a3af7fa37f98b0405657198c0a24f2ac
Bug: skia:11342, skia:11319
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/376136
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
6 files changed