Retire SkShader::kSupports4f_Flag

include/core/SkShader.h

Index: include/core/SkShader.h
diff --git a/include/core/SkShader.h b/include/core/SkShader.h
index 72cd4a2dbeec7535bcf5e2b5db178fb553e9cc9a..0645809fe6873a9acbc6190895f109a83b8ea465 100644
--- a/include/core/SkShader.h
+++ b/include/core/SkShader.h
@@ -82,7 +82,10 @@ public:
             shadeSpan().
          */
         kConstInY32_Flag = 1 << 1,
-        kSupports4f_Flag = 1 << 2,
+
+        /** hint for the blitter that 4f is the preferred shading mode.
+         */
+        kPrefers4f_Flag  = 1 << 2,
     };
 
     /**
@@ -130,10 +133,6 @@ public:
          */
         virtual uint32_t getFlags() const { return 0; }
 
-        bool supports4f() const {
-            return SkToBool(this->getFlags() & kSupports4f_Flag);
-        }
-
         /**
          *  Called for each span of the object being drawn. Your subclass should
          *  set the appropriate colors (with premultiplied alpha) that correspond