Expose '--notexturecache' command line argument to gm.
Expose '--notexturecache' command line argument to gm.

Pass '--notexturecache' to gm to resize the Ganesh texture cache to 0.  This stresses Ganesh's behaviour after a cache purge operation.
Review URL: https://codereview.appspot.com/5569079

git-svn-id: e8541e15acce502a64c929015570ad1648e548cd@3123 2bbb7eff-a529-9590-31e7-b0007b416f81

Hankuo/color-emoji.skia,MatChung/color-emoji.skia,Frankie-666/color-emoji.skia,MatChung/color-emoji.skia,Hankuo/color-emoji.skia,hbwhlklive/color-emoji.skia,Hankuo/color-emoji.skia,hbwhlklive/color-emoji.skia,Hankuo/color-emoji.skia,hbwhlklive/color-emoji.skia,Frankie-666/color-emoji.skia,MatChung/color-emoji.skia,MatChung/color-emoji.skia,Frankie-666/color-emoji.skia,MatChung/color-emoji.skia,MatChung/color-emoji.skia,Hankuo/color-emoji.skia,Frankie-666/color-emoji.skia,Frankie-666/color-emoji.skia,Frankie-666/color-emoji.skia,Hankuo/color-emoji.skia,hbwhlklive/color-emoji.skia,hbwhlklive/color-emoji.skia,hbwhlklive/color-emoji.skia