Add faster powf approximation for Android.

expectations/gm/ignored-tests.txt

Index: expectations/gm/ignored-tests.txt
diff --git a/expectations/gm/ignored-tests.txt b/expectations/gm/ignored-tests.txt
index c97a0b9de23851fa466a54354e0d4064b6aa3709..83b6fe158ea8ec8756cc83c3fc7af5c022ed8812 100644
--- a/expectations/gm/ignored-tests.txt
+++ b/expectations/gm/ignored-tests.txt
@@ -45,3 +45,92 @@ bleed
 blurquickreject
 blurrects
 bigblurs
+
+# jvanverth:
+# Android text gamma changes slightly
+# https://codereview.chromium.org/348153002/
+imageblurtiled
+filterbitmap_text_3.00pt
+filterbitmap_text_7.00pt
+filterbitmap_text_10.00pt
+texteffects
+gammatext
+fontscaler
+imageblur_large
+imageblur
+convex_poly_clip
+fontcache
+varied_text_ignorable_clip_lcd
+imageresizetiled
+fontmgr_iter
+varied_text_clipped_no_lcd
+typefacestyles_kerning
+downsamplebitmap_text_high_72.00pt
+downsamplebitmap_text_medium_72.00pt
+degeneratesegments
+verttext2
+varied_text_clipped_lcd
+cubicclosepath
+quadclosepath
+lineclosepath
+cubicpath
+quadpath
+linepath
+imagefiltersgraph
+gradtext
+drawlooper
+emptypath
+lcdtext
+matrixconvolution
+typefacestyles
+morphology
+downsamplebitmap_text_low_72.00pt
+fontmgr_match
+lighting
+imagemagnifier
+xfermodes2
+downsamplebitmap_text_none_72.00pt
+displacement
+xfermodes
+shadertext
+arithmode
+verttext
+bitmapsource
+xfermodes3
+typeface
+twopointconical
+stroketext
+complexclip_aa
+complexclip_bw
+stroke-fill
+tileimagefilter
+getpostextpath
+drawbitmaprect
+simpleaaclip_aaclip
+simpleaaclip_path
+simpleaaclip_rect
+shadertext2
+blurs
+complexclip_aa_layer
+complexclip_bw_layer
+scaled_tilemodes_npot
+tilemodes
+tilemodes_npot
+scaled_tilemodes
+bitmapfilters
+imagefiltersbase
+pictureimagefilter
+srcmode
+image-surface
+scaled_tilemode_bitmap
+scaled_tilemode_gradient
+tilemode_bitmap
+tilemode_gradient
+xfermodeimagefilter
+dropshadowimagefilter
+internal_links
+offsetimagefilter
+bitmapcopy
+samplerstress
+imagefilterscropped
+poly2poly