use floor for mip-level choice
use floor for mip-level choice

this chrome change must land first: https://codereview.chromium.org/1131663002/

BUG=skia:

Review URL: https://codereview.chromium.org/1131613002

rubenvb/skia,tmpvar/skia.cc,boulzordev/android_external_skia,AOSP-YU/platform_external_skia,noselhq/skia,vanish87/skia,OneRom/external_skia,geekboxzone/mmallow_external_skia,YUPlayGodDev/platform_external_skia,aosp-mirror/platform_external_skia,vanish87/skia,tmpvar/skia.cc,tmpvar/skia.cc,vanish87/skia,MarshedOut/android_external_skia,timduru/platform-external-skia,VRToxin-AOSP/android_external_skia,nvoron23/skia,nvoron23/skia,aosp-mirror/platform_external_skia,geekboxzone/mmallow_external_skia,tmpvar/skia.cc,Infinitive-OS/platform_external_skia,google/skia,w3nd1go/android_external_skia,MonkeyZZZZ/platform_external_skia,UBERMALLOW/external_skia,todotodoo/skia,google/skia,HalCanary/skia-hc,tmpvar/skia.cc,pcwalton/skia,YUPlayGodDev/platform_external_skia,shahrzadmn/skia,BrokenROM/external_skia,vanish87/skia,google/skia,Jichao/skia,OneRom/external_skia,MonkeyZZZZ/platform_external_skia,tmpvar/skia.cc,ominux/skia,MonkeyZZZZ/platform_external_skia,todotodoo/skia,nvoron23/skia,rubenvb/skia,tmpvar/skia.cc,AOSP-YU/platform_external_skia,geekboxzone/mmallow_external_skia,vanish87/skia,AOSP-YU/platform_external_skia,Jichao/skia,nfxosp/platform_external_skia,ominux/skia,Jichao/skia,noselhq/skia,UBERMALLOW/external_skia,TeamTwisted/external_skia,rubenvb/skia,shahrzadmn/skia,noselhq/skia,todotodoo/skia,UBERMALLOW/external_skia,BrokenROM/external_skia,UBERMALLOW/external_skia,geekboxzone/mmallow_external_skia,Infinitive-OS/platform_external_skia,rubenvb/skia,shahrzadmn/skia,MinimalOS-AOSP/platform_external_skia,invisiblek/android_external_skia,pcwalton/skia,todotodoo/skia,PAC-ROM/android_external_skia,boulzordev/android_external_skia,pcwalton/skia,aosp-mirror/platform_external_skia,TeamExodus/external_skia,MarshedOut/android_external_skia,invisiblek/android_external_skia,YUPlayGodDev/platform_external_skia,Jichao/skia,pcwalton/skia,PAC-ROM/android_external_skia,Hikari-no-Tenshi/android_external_skia,TeamExodus/external_skia,OneRom/external_skia,AOSP-YU/platform_external_skia,AOSPB/external_skia,nfxosp/platform_external_skia,spezi77/android_external_skia,todotodoo/skia,PAC-ROM/android_external_skia,OneRom/external_skia,MinimalOS-AOSP/platform_external_skia,qrealka/skia-hc,AOSPB/external_skia,UBERMALLOW/external_skia,AOSPB/external_skia,VRToxin-AOSP/android_external_skia,timduru/platform-external-skia,Infinitive-OS/platform_external_skia,geekboxzone/mmallow_external_skia,TeamExodus/external_skia,Hikari-no-Tenshi/android_external_skia,w3nd1go/android_external_skia,shahrzadmn/skia,aosp-mirror/platform_external_skia,AOSP-YU/platform_external_skia,TeamExodus/external_skia,boulzordev/android_external_skia,YUPlayGodDev/platform_external_skia,qrealka/skia-hc,todotodoo/skia,aosp-mirror/platform_external_skia,OneRom/external_skia,pcwalton/skia,w3nd1go/android_external_skia,YUPlayGodDev/platform_external_skia,Jichao/skia,nvoron23/skia,Hikari-no-Tenshi/android_external_skia,nvoron23/skia,PAC-ROM/android_external_skia,UBERMALLOW/external_skia,boulzordev/android_external_skia,UBERMALLOW/external_skia,PAC-ROM/android_external_skia,AOSPB/external_skia,rubenvb/skia,nfxosp/platform_external_skia,nvoron23/skia,pcwalton/skia,rubenvb/skia,nfxosp/platform_external_skia,TeamTwisted/external_skia,PAC-ROM/android_external_skia,nvoron23/skia,Infinitive-OS/platform_external_skia,timduru/platform-external-skia,Infinitive-OS/platform_external_skia,UBERMALLOW/external_skia,Infinitive-OS/platform_external_skia,geekboxzone/mmallow_external_skia,qrealka/skia-hc,BrokenROM/external_skia,HalCanary/skia-hc,vanish87/skia,google/skia,PAC-ROM/android_external_skia,shahrzadmn/skia,w3nd1go/android_external_skia,MarshedOut/android_external_skia,spezi77/android_external_skia,google/skia,Jichao/skia,VRToxin-AOSP/android_external_skia,shahrzadmn/skia,BrokenROM/external_skia,vanish87/skia,shahrzadmn/skia,Jichao/skia,MarshedOut/android_external_skia,invisiblek/android_external_skia,geekboxzone/mmallow_external_skia,google/skia,VRToxin-AOSP/android_external_skia,MarshedOut/android_external_skia,nfxosp/platform_external_skia,MinimalOS-AOSP/platform_external_skia,YUPlayGodDev/platform_external_skia,invisiblek/android_external_skia,MarshedOut/android_external_skia,w3nd1go/android_external_skia,tmpvar/skia.cc,noselhq/skia,BrokenROM/external_skia,VRToxin-AOSP/android_external_skia,aosp-mirror/platform_external_skia,spezi77/android_external_skia,todotodoo/skia,ominux/skia,boulzordev/android_external_skia,boulzordev/android_external_skia,ominux/skia,noselhq/skia,aosp-mirror/platform_external_skia,VRToxin-AOSP/android_external_skia,spezi77/android_external_skia,Hikari-no-Tenshi/android_external_skia,MinimalOS-AOSP/platform_external_skia,nfxosp/platform_external_skia,noselhq/skia,MinimalOS-AOSP/platform_external_skia,HalCanary/skia-hc,TeamTwisted/external_skia,HalCanary/skia-hc,AOSPB/external_skia,BrokenROM/external_skia,MonkeyZZZZ/platform_external_skia,invisiblek/android_external_skia,ominux/skia,qrealka/skia-hc,timduru/platform-external-skia,MonkeyZZZZ/platform_external_skia,pcwalton/skia,boulzordev/android_external_skia,MinimalOS-AOSP/platform_external_skia,PAC-ROM/android_external_skia,invisiblek/android_external_skia,shahrzadmn/skia,Hikari-no-Tenshi/android_external_skia,ominux/skia,w3nd1go/android_external_skia,nfxosp/platform_external_skia,HalCanary/skia-hc,HalCanary/skia-hc,YUPlayGodDev/platform_external_skia,qrealka/skia-hc,noselhq/skia,BrokenROM/external_skia,w3nd1go/android_external_skia,spezi77/android_external_skia,AOSP-YU/platform_external_skia,MinimalOS-AOSP/platform_external_skia,ominux/skia,noselhq/skia,MinimalOS-AOSP/platform_external_skia,HalCanary/skia-hc,AOSP-YU/platform_external_skia,MarshedOut/android_external_skia,TeamExodus/external_skia,HalCanary/skia-hc,Infinitive-OS/platform_external_skia,qrealka/skia-hc,MonkeyZZZZ/platform_external_skia,HalCanary/skia-hc,vanish87/skia,shahrzadmn/skia,rubenvb/skia,geekboxzone/mmallow_external_skia,TeamTwisted/external_skia,OneRom/external_skia,MarshedOut/android_external_skia,w3nd1go/android_external_skia,MinimalOS-AOSP/platform_external_skia,rubenvb/skia,spezi77/android_external_skia,aosp-mirror/platform_external_skia,TeamTwisted/external_skia,AOSPB/external_skia,vanish87/skia,TeamExodus/external_skia,YUPlayGodDev/platform_external_skia,Hikari-no-Tenshi/android_external_skia,AOSP-YU/platform_external_skia,pcwalton/skia,PAC-ROM/android_external_skia,invisiblek/android_external_skia,TeamExodus/external_skia,Hikari-no-Tenshi/android_external_skia,TeamTwisted/external_skia,Jichao/skia,MonkeyZZZZ/platform_external_skia,TeamTwisted/external_skia,timduru/platform-external-skia,boulzordev/android_external_skia,AOSPB/external_skia,Jichao/skia,todotodoo/skia,google/skia,Infinitive-OS/platform_external_skia,AOSPB/external_skia,nfxosp/platform_external_skia,nfxosp/platform_external_skia,invisiblek/android_external_skia,MonkeyZZZZ/platform_external_skia,noselhq/skia,OneRom/external_skia,qrealka/skia-hc,Hikari-no-Tenshi/android_external_skia,ominux/skia,TeamExodus/external_skia,OneRom/external_skia,todotodoo/skia,google/skia,rubenvb/skia,BrokenROM/external_skia,google/skia,TeamTwisted/external_skia,UBERMALLOW/external_skia,timduru/platform-external-skia,aosp-mirror/platform_external_skia,boulzordev/android_external_skia,w3nd1go/android_external_skia,TeamTwisted/external_skia,rubenvb/skia,pcwalton/skia,qrealka/skia-hc,nvoron23/skia,YUPlayGodDev/platform_external_skia,OneRom/external_skia,MarshedOut/android_external_skia,google/skia,timduru/platform-external-skia,AOSPB/external_skia,VRToxin-AOSP/android_external_skia,tmpvar/skia.cc,HalCanary/skia-hc,AOSP-YU/platform_external_skia,TeamExodus/external_skia,ominux/skia,VRToxin-AOSP/android_external_skia,Infinitive-OS/platform_external_skia,nvoron23/skia,MonkeyZZZZ/platform_external_skia,aosp-mirror/platform_external_skia,VRToxin-AOSP/android_external_skia,geekboxzone/mmallow_external_skia