Possible optimization to SkString
Possible optimization to SkString

BUG=skia:

Review URL: https://codereview.chromium.org/679433003

Infinitive-OS/platform_external_skia,AOSP-YU/platform_external_skia,shahrzadmn/skia,TeamTwisted/external_skia,nfxosp/platform_external_skia,AOSPB/external_skia,scroggo/skia,geekboxzone/mmallow_external_skia,ominux/skia,HalCanary/skia-hc,invisiblek/android_external_skia,shahrzadmn/skia,Igalia/skia,rubenvb/skia,Infinitive-OS/platform_external_skia,MarshedOut/android_external_skia,tmpvar/skia.cc,scroggo/skia,DiamondLovesYou/skia-sys,TeamTwisted/external_skia,google/skia,scroggo/skia,MinimalOS-AOSP/platform_external_skia,qrealka/skia-hc,MinimalOS-AOSP/platform_external_skia,Igalia/skia,PAC-ROM/android_external_skia,todotodoo/skia,amyvmiwei/skia,tmpvar/skia.cc,pcwalton/skia,pcwalton/skia,qrealka/skia-hc,qrealka/skia-hc,timduru/platform-external-skia,todotodoo/skia,tmpvar/skia.cc,boulzordev/android_external_skia,nfxosp/platform_external_skia,DiamondLovesYou/skia-sys,MinimalOS-AOSP/platform_external_skia,w3nd1go/android_external_skia,rubenvb/skia,UBERMALLOW/external_skia,HalCanary/skia-hc,w3nd1go/android_external_skia,AOSPB/external_skia,invisiblek/android_external_skia,noselhq/skia,samuelig/skia,aosp-mirror/platform_external_skia,qrealka/skia-hc,shahrzadmn/skia,google/skia,noselhq/skia,Igalia/skia,YUPlayGodDev/platform_external_skia,geekboxzone/mmallow_external_skia,ominux/skia,geekboxzone/mmallow_external_skia,pcwalton/skia,UBERMALLOW/external_skia,aosp-mirror/platform_external_skia,scroggo/skia,Jichao/skia,OneRom/external_skia,w3nd1go/android_external_skia,MarshedOut/android_external_skia,noselhq/skia,OneRom/external_skia,w3nd1go/android_external_skia,Hikari-no-Tenshi/android_external_skia,timduru/platform-external-skia,MonkeyZZZZ/platform_external_skia,chenlian2015/skia_from_google,pcwalton/skia,noselhq/skia,tmpvar/skia.cc,spezi77/android_external_skia,Jichao/skia,HalCanary/skia-hc,jtg-gg/skia,shahrzadmn/skia,spezi77/android_external_skia,nvoron23/skia,shahrzadmn/skia,Infinitive-OS/platform_external_skia,TeamTwisted/external_skia,google/skia,AOSP-YU/platform_external_skia,nvoron23/skia,geekboxzone/mmallow_external_skia,rubenvb/skia,Jichao/skia,jtg-gg/skia,ominux/skia,nfxosp/platform_external_skia,VRToxin-AOSP/android_external_skia,AOSPB/external_skia,samuelig/skia,AOSP-YU/platform_external_skia,spezi77/android_external_skia,rubenvb/skia,amyvmiwei/skia,VRToxin-AOSP/android_external_skia,noselhq/skia,invisiblek/android_external_skia,MinimalOS-AOSP/platform_external_skia,boulzordev/android_external_skia,TeamExodus/external_skia,nvoron23/skia,AOSPB/external_skia,AOSP-YU/platform_external_skia,google/skia,HalCanary/skia-hc,jtg-gg/skia,Infinitive-OS/platform_external_skia,chenlian2015/skia_from_google,nfxosp/platform_external_skia,nfxosp/platform_external_skia,noselhq/skia,YUPlayGodDev/platform_external_skia,amyvmiwei/skia,nvoron23/skia,geekboxzone/mmallow_external_skia,todotodoo/skia,amyvmiwei/skia,boulzordev/android_external_skia,w3nd1go/android_external_skia,DiamondLovesYou/skia-sys,shahrzadmn/skia,geekboxzone/mmallow_external_skia,PAC-ROM/android_external_skia,Infinitive-OS/platform_external_skia,boulzordev/android_external_skia,Jichao/skia,Igalia/skia,Jichao/skia,MonkeyZZZZ/platform_external_skia,Hikari-no-Tenshi/android_external_skia,BrokenROM/external_skia,vanish87/skia,invisiblek/android_external_skia,noselhq/skia,scroggo/skia,Igalia/skia,invisiblek/android_external_skia,MinimalOS-AOSP/platform_external_skia,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,YUPlayGodDev/platform_external_skia,aosp-mirror/platform_external_skia,invisiblek/android_external_skia,MarshedOut/android_external_skia,OneRom/external_skia,PAC-ROM/android_external_skia,google/skia,DiamondLovesYou/skia-sys,MonkeyZZZZ/platform_external_skia,rubenvb/skia,TeamExodus/external_skia,TeamExodus/external_skia,nvoron23/skia,MinimalOS-AOSP/platform_external_skia,MinimalOS-AOSP/platform_external_skia,BrokenROM/external_skia,google/skia,MarshedOut/android_external_skia,Hikari-no-Tenshi/android_external_skia,PAC-ROM/android_external_skia,MinimalOS-AOSP/platform_external_skia,AOSP-YU/platform_external_skia,jtg-gg/skia,samuelig/skia,timduru/platform-external-skia,samuelig/skia,UBERMALLOW/external_skia,aosp-mirror/platform_external_skia,vanish87/skia,VRToxin-AOSP/android_external_skia,HalCanary/skia-hc,ominux/skia,vanish87/skia,pcwalton/skia,ominux/skia,vanish87/skia,google/skia,OneRom/external_skia,Infinitive-OS/platform_external_skia,Hikari-no-Tenshi/android_external_skia,MonkeyZZZZ/platform_external_skia,AOSPB/external_skia,google/skia,OneRom/external_skia,MarshedOut/android_external_skia,YUPlayGodDev/platform_external_skia,TeamTwisted/external_skia,TeamExodus/external_skia,Infinitive-OS/platform_external_skia,invisiblek/android_external_skia,geekboxzone/mmallow_external_skia,DiamondLovesYou/skia-sys,todotodoo/skia,MonkeyZZZZ/platform_external_skia,YUPlayGodDev/platform_external_skia,samuelig/skia,jtg-gg/skia,Infinitive-OS/platform_external_skia,TeamTwisted/external_skia,pcwalton/skia,AOSPB/external_skia,OneRom/external_skia,AOSPB/external_skia,AOSP-YU/platform_external_skia,Hikari-no-Tenshi/android_external_skia,google/skia,boulzordev/android_external_skia,PAC-ROM/android_external_skia,noselhq/skia,pcwalton/skia,HalCanary/skia-hc,samuelig/skia,chenlian2015/skia_from_google,todotodoo/skia,qrealka/skia-hc,vanish87/skia,vanish87/skia,amyvmiwei/skia,jtg-gg/skia,chenlian2015/skia_from_google,nfxosp/platform_external_skia,qrealka/skia-hc,BrokenROM/external_skia,w3nd1go/android_external_skia,DiamondLovesYou/skia-sys,VRToxin-AOSP/android_external_skia,pcwalton/skia,aosp-mirror/platform_external_skia,UBERMALLOW/external_skia,HalCanary/skia-hc,rubenvb/skia,UBERMALLOW/external_skia,Igalia/skia,noselhq/skia,spezi77/android_external_skia,todotodoo/skia,OneRom/external_skia,boulzordev/android_external_skia,PAC-ROM/android_external_skia,TeamExodus/external_skia,nvoron23/skia,qrealka/skia-hc,TeamExodus/external_skia,aosp-mirror/platform_external_skia,OneRom/external_skia,shahrzadmn/skia,TeamTwisted/external_skia,ominux/skia,MonkeyZZZZ/platform_external_skia,chenlian2015/skia_from_google,w3nd1go/android_external_skia,AOSP-YU/platform_external_skia,Hikari-no-Tenshi/android_external_skia,w3nd1go/android_external_skia,nfxosp/platform_external_skia,scroggo/skia,Igalia/skia,Infinitive-OS/platform_external_skia,PAC-ROM/android_external_skia,rubenvb/skia,rubenvb/skia,VRToxin-AOSP/android_external_skia,YUPlayGodDev/platform_external_skia,invisiblek/android_external_skia,aosp-mirror/platform_external_skia,TeamTwisted/external_skia,MarshedOut/android_external_skia,timduru/platform-external-skia,TeamTwisted/external_skia,chenlian2015/skia_from_google,todotodoo/skia,aosp-mirror/platform_external_skia,YUPlayGodDev/platform_external_skia,chenlian2015/skia_from_google,Igalia/skia,HalCanary/skia-hc,vanish87/skia,rubenvb/skia,timduru/platform-external-skia,VRToxin-AOSP/android_external_skia,amyvmiwei/skia,tmpvar/skia.cc,geekboxzone/mmallow_external_skia,vanish87/skia,scroggo/skia,MonkeyZZZZ/platform_external_skia,UBERMALLOW/external_skia,AOSP-YU/platform_external_skia,vanish87/skia,rubenvb/skia,spezi77/android_external_skia,todotodoo/skia,aosp-mirror/platform_external_skia,MarshedOut/android_external_skia,OneRom/external_skia,w3nd1go/android_external_skia,tmpvar/skia.cc,YUPlayGodDev/platform_external_skia,shahrzadmn/skia,amyvmiwei/skia,boulzordev/android_external_skia,boulzordev/android_external_skia,BrokenROM/external_skia,scroggo/skia,MonkeyZZZZ/platform_external_skia,MarshedOut/android_external_skia,boulzordev/android_external_skia,BrokenROM/external_skia,MinimalOS-AOSP/platform_external_skia,aosp-mirror/platform_external_skia,AOSPB/external_skia,UBERMALLOW/external_skia,pcwalton/skia,TeamTwisted/external_skia,tmpvar/skia.cc,AOSPB/external_skia,YUPlayGodDev/platform_external_skia,spezi77/android_external_skia,Hikari-no-Tenshi/android_external_skia,google/skia,nfxosp/platform_external_skia,ominux/skia,timduru/platform-external-skia,BrokenROM/external_skia,TeamExodus/external_skia,VRToxin-AOSP/android_external_skia,Jichao/skia,nvoron23/skia,UBERMALLOW/external_skia,Jichao/skia,samuelig/skia,shahrzadmn/skia,PAC-ROM/android_external_skia,VRToxin-AOSP/android_external_skia,BrokenROM/external_skia,qrealka/skia-hc,TeamExodus/external_skia,ominux/skia,tmpvar/skia.cc,ominux/skia,amyvmiwei/skia,TeamExodus/external_skia,tmpvar/skia.cc,Jichao/skia,AOSP-YU/platform_external_skia,todotodoo/skia,nfxosp/platform_external_skia,PAC-ROM/android_external_skia,UBERMALLOW/external_skia,MonkeyZZZZ/platform_external_skia,samuelig/skia,BrokenROM/external_skia,nvoron23/skia,DiamondLovesYou/skia-sys,timduru/platform-external-skia,nvoron23/skia,jtg-gg/skia,geekboxzone/mmallow_external_skia,HalCanary/skia-hc,Jichao/skia,VRToxin-AOSP/android_external_skia,MarshedOut/android_external_skia