remove U16 support, just support F16

src/core/SkBlitter_PM4f.cpp

Index: src/core/SkBlitter_PM4f.cpp
diff --git a/src/core/SkBlitter_PM4f.cpp b/src/core/SkBlitter_PM4f.cpp
index 820d72cc2e6da8dee07754cd3ab032af6b019565..323df76736c4f1d7eacc293086ff98b335e1342b 100644
--- a/src/core/SkBlitter_PM4f.cpp
+++ b/src/core/SkBlitter_PM4f.cpp
@@ -363,8 +363,8 @@ struct State32 : State4f {
 
     SkXfermode::LCD32Proc getLCDProc(uint32_t oneOrManyFlag) const {
         uint32_t flags = fFlags & 1;
-        if (!(fFlags & SkXfermode::kDstIsSRGB_D32Flag)) {
-            flags |= SkXfermode::kDstIsLinearInt_LCDFlag;
+        if (fFlags & SkXfermode::kDstIsSRGB_D32Flag) {
+            flags |= SkXfermode::kDstIsSRGB_LCDFlag;
         }
         return SkXfermode::GetLCD32Proc(flags | oneOrManyFlag);
     }
@@ -377,28 +377,23 @@ struct State32 : State4f {
 struct State64 : State4f {
     typedef uint64_t    DstType;
 
-    SkXfermode::D64Proc fProc1;
-    SkXfermode::D64Proc fProcN;
+    SkXfermode::F16Proc fProc1;
+    SkXfermode::F16Proc fProcN;
 
     State64(const SkImageInfo& info, const SkPaint& paint, const SkShader::Context* shaderContext)
         : State4f(info, paint, shaderContext)
     {
         if (is_opaque(paint, shaderContext)) {
-            fFlags |= SkXfermode::kSrcIsOpaque_D64Flag;
+            fFlags |= SkXfermode::kSrcIsOpaque_F16Flag;
         }
-        if (kRGBA_F16_SkColorType == info.colorType()) {
-            fFlags |= SkXfermode::kDstIsFloat16_D64Flag;
-        }
-        fProc1 = SkXfermode::GetD64Proc(fXfer, fFlags | SkXfermode::kSrcIsSingle_D64Flag);
-        fProcN = SkXfermode::GetD64Proc(fXfer, fFlags);
+        SkASSERT(kRGBA_F16_SkColorType == info.colorType());
+        fProc1 = SkXfermode::GetF16Proc(fXfer, fFlags | SkXfermode::kSrcIsSingle_F16Flag);
+        fProcN = SkXfermode::GetF16Proc(fXfer, fFlags);
     }
 
-    SkXfermode::LCD64Proc getLCDProc(uint32_t oneOrManyFlag) const {
+    SkXfermode::LCF16Proc getLCDProc(uint32_t oneOrManyFlag) const {
         uint32_t flags = fFlags & 1;
-        if (!(fFlags & SkXfermode::kDstIsFloat16_D64Flag)) {
-            flags |= SkXfermode::kDstIsLinearInt_LCDFlag;
-        }
-        return SkXfermode::GetLCD64Proc(flags | oneOrManyFlag);
+        return SkXfermode::GetLCF16Proc(flags | oneOrManyFlag);
     }
 
     static DstType* WritableAddr(const SkPixmap& device, int x, int y) {