ensure 4-byte alignment for storage, as SkWriterBuffer requires it
ensure 4-byte alignment for storage, as SkWriterBuffer requires it

BUG=skia:3244

Review URL: https://codereview.chromium.org/805803002

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