detect when we can filter bitmaps/images directly, w/o a tmp layer

visual bench run on Mac Pro

curr/maxrss	loops	min	median	mean	max	stddev	samples   	config	bench
 100/100 MB	16	412µs	413µs	413µs	414µs	0%	▄▁▇▄▄▄▄█▄▃▅	gpu	warmupbench
 101/102 MB	32	547µs	548µs	611µs	1.24ms	34%	█▁▁▁▁▁▁▁▁▁▁	gpu	image-filter-sprite-draw-image
 102/103 MB	32	547µs	548µs	721µs	1.23ms	41%	█▁▇▁▁█▁▁▁▁▁	gpu	image-filter-sprite-draw-bitmap
 103/103 MB	64	546µs	546µs	546µs	547µs	0%	▆▄▂▁▇█▅▇▅▇▃	gpu	image-filter-sprite-draw-sprite

Should have no effect on Chrome while SK_SUPPORT_LEGACY_LAYER_BITMAP_IMAGEFILTERS is defined (which it is in chrome)

BUG=skia:1073

Review URL: https://codereview.chromium.org/1491293002
7 files changed