Implement 'stepToBreakpoint' in Trace player.

This allows the user to run up to a specified line (or until execution
is complete).

Change-Id: Ied34798d2df1b4a9e1d723c8d2eff3d579ca9b2d
Bug: skia:12747
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/485860
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
3 files changed