SkBlitter_RGB16: Add device-specific optimization hooks
SkBlitter_RGB16: Add device-specific optimization hooks

Change-Id: I18bf4825669fef6fcc10e5d48271e7ea9abb3ed6
(cherry picked from commit 5d5e3dd98e15a5d25fcddf41f00dc5989942d094)
(cherry picked from commit afbd633b035a8b8f6017f52f6ad398a076aee841)
(cherry picked from commit 814fe785689f0b018283fbc2b02a2d230f0221cb)

CandyKat/external_skia,MagicDevTeam/android_external_skia,ChameleonOS/android_external_skia,MagicDevTeam/android_external_skia,MyAOSP/external_skia,TripNRaVeR/android_external_skia,TripNRaVeR/android_external_skia,MyAOSP/external_skia,VanirAOSP/external_skia,AOSP-S4-KK/platform_external_skia,androidarmv6/android_external_skia,SuperNexus/android_external_skia,Mahdi-Rom/android_external_skia,Mahdi-Rom/android_external_skia,Nico60/external_skia,SuperNexus/android_external_skia,MyAOSP/external_skia,MagicDevTeam/android_external_skia,StelixROM/android_external_skia,CandyKat/external_skia,IllusionRom-deprecated/android_platform_external_skia,marlontoe/android_external_skia,androidarmv6/android_external_skia,StelixROM/android_external_skia,StelixROM/android_external_skia,Nico60/external_skia,Nico60/external_skia,AOSP-S4-KK/platform_external_skia,Mahdi-Rom/android_external_skia,marlontoe/android_external_skia,SuperNexus/android_external_skia,StelixROM/android_external_skia,StelixROM/android_external_skia,Mahdi-Rom/android_external_skia,AOKP/external_skia,StelixROM/android_external_skia,CandyKat/external_skia,androidarmv6/android_external_skia,ChameleonOS/android_external_skia,AOKP/external_skia,SuperNexus/android_external_skia,VanirAOSP/external_skia,Nico60/external_skia,VanirAOSP/external_skia,marlontoe/android_external_skia,CandyKat/external_skia,VanirAOSP/external_skia,MyAOSP/external_skia,IllusionRom-deprecated/android_platform_external_skia,androidarmv6/android_external_skia,ChameleonOS/android_external_skia,AOKP/external_skia,marlontoe/android_external_skia,MagicDevTeam/android_external_skia,AOSP-S4-KK/platform_external_skia,marlontoe/android_external_skia,TripNRaVeR/android_external_skia,TripNRaVeR/android_external_skia,androidarmv6/android_external_skia,androidarmv6/android_external_skia,Mahdi-Rom/android_external_skia,IllusionRom-deprecated/android_platform_external_skia,CandyKat/external_skia,AOSP-S4-KK/platform_external_skia,VanirAOSP/external_skia,androidarmv6/android_external_skia,AOKP/external_skia,androidarmv6/android_external_skia,MyAOSP/external_skia,ChameleonOS/android_external_skia,IllusionRom-deprecated/android_platform_external_skia,AOSP-S4-KK/platform_external_skia,Nico60/external_skia