ccpr: Initialize the atlas size more intelligently

Rather than always starting the atlas at 1024 x 1024, begin with the
first pow2 dimensions whose area is theoretically large enough to
contain the pending paths.

Bug: skia:
Change-Id: I263e77ff6a697e865f6b3b62b9df7002225f9544
Reviewed-on: https://skia-review.googlesource.com/133660
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
11 files changed