Make GrGLConfigConversionEffect work for Imagination and some other GPUs.

src/gpu/effects/GrConfigConversionEffect.h

Index: src/gpu/effects/GrConfigConversionEffect.h
diff --git a/src/gpu/effects/GrConfigConversionEffect.h b/src/gpu/effects/GrConfigConversionEffect.h
index 169c3d7db8fabc7e19480e4554550be8a09f4b02..20667e0bd251f065830f5983f50da7b011b16dae 100644
--- a/src/gpu/effects/GrConfigConversionEffect.h
+++ b/src/gpu/effects/GrConfigConversionEffect.h
@@ -30,6 +30,10 @@ public:
         kMulByAlpha_RoundDown_PMConversion,
         kDivByAlpha_RoundUp_PMConversion,
         kDivByAlpha_RoundDown_PMConversion,
+        kMulByAlpha_RoundUp_HIGHP_PMConversion,
+        kMulByAlpha_RoundDown_HIGHP_PMConversion,
+        kDivByAlpha_RoundUp_HIGHP_PMConversion,
+        kDivByAlpha_RoundDown_HIGHP_PMConversion,
 
         kPMConversionCnt
     };