Fold analytic clip FPs into GrReducedClip

Perf result on Pixel phone (sorted by impact):

  GEOMEAN                               6.73 -> 6.49 ms   [96% ]

  top25desk_pinterest.skp               0.45 -> 0.49 ms   [107%]
  desk_pokemonwiki.skp                  14.6 -> 15.9 ms   [106%]
  keymobi_pinterest.skp                 0.47 -> 0.49 ms   [104%]
  ...
  keymobi_androidpolice_com_2012_.skp   3.69 -> 3.09 ms   [83% ]
  keymobi_shop_mobileweb_ebay_com.skp   2.90 -> 2.29 ms   [78% ]
  keymobi_boingboing_net.skp            2.95 -> 2.29 ms   [76% ]
  desk_jsfiddlebigcar.skp               1.79 -> 1.29 ms   [71% ]
  keymobi_m_youtube_com_watch_v_9.skp   12.9 -> 9.09 ms   [70% ]
  keymobi_blogger.skp                   3.80 -> 2.69 ms   [70% ]
  keymobi_sfgate_com_.skp               8.16 -> 5.69 ms   [69% ]

Cleaner code, improved skps, slightly better geometric mean time.

Pixel C is mostly unaffected, presumably because it uses window
rectangles.

Bug: skia:7190
Change-Id: I9c7f3512ca57e1d1afcd42865357b63ffcc192ce
Reviewed-on: https://skia-review.googlesource.com/66280
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
5 files changed