remove disable aa/dither flags from Props -- never used

include/core/SkSurfaceProps.h

Index: include/core/SkSurfaceProps.h
diff --git a/include/core/SkSurfaceProps.h b/include/core/SkSurfaceProps.h
index 735561f1dc9180a1cb9f044fa23856ae915f08c1..da04d1fe929846ef6046d9d2ddd220257fa29b68 100644
--- a/include/core/SkSurfaceProps.h
+++ b/include/core/SkSurfaceProps.h
@@ -51,9 +51,7 @@ static inline bool SkPixelGeometryIsV(SkPixelGeometry geo) {
 class SK_API SkSurfaceProps {
 public:
     enum Flags {
-        kDisallowAntiAlias_Flag         = 1 << 0,
-        kDisallowDither_Flag            = 1 << 1,
-        kUseDeviceIndependentFonts_Flag = 1 << 2,
+        kUseDeviceIndependentFonts_Flag = 1 << 0,
     };
     /** Deprecated alias used by Chromium. Will be removed. */
     static const Flags kUseDistanceFieldFonts_Flag = kUseDeviceIndependentFonts_Flag;
@@ -70,8 +68,6 @@ public:
     uint32_t flags() const { return fFlags; }
     SkPixelGeometry pixelGeometry() const { return fPixelGeometry; }
 
-    bool isDisallowAA() const { return SkToBool(fFlags & kDisallowAntiAlias_Flag); }
-    bool isDisallowDither() const { return SkToBool(fFlags & kDisallowDither_Flag); }
     bool isUseDeviceIndependentFonts() const {
         return SkToBool(fFlags & kUseDeviceIndependentFonts_Flag);
     }