temporarily copy SkBase64.h until flutter can
move to using the one in include/util
Copy TRACE_EVENT_PHASE_* into its own file
in include/util; the only part of SkTraceEventCommon.h
that flutter needs.
R=reed@google.com,chinmaygarde@google.com
Bug: skia:7741
Change-Id: I8671edbf1d6b6b868bde98aa9ad04abcb85a43a0
Reviewed-on: https://skia-review.googlesource.com/135870
Reviewed-by: Chinmay Garde <chinmaygarde@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Cary Clark <caryclark@skia.org>
