Remove kDisableBlend_BlendOptFlag as it is no longer needed

src/gpu/GrDrawState.h

Index: src/gpu/GrDrawState.h
diff --git a/src/gpu/GrDrawState.h b/src/gpu/GrDrawState.h
index c1dd9dcd36f61102333a1ef87cceaa15b141bdbe..d1b7a66f5ca454c464d6252c3788bafa2a5630e3 100644
--- a/src/gpu/GrDrawState.h
+++ b/src/gpu/GrDrawState.h
@@ -521,28 +521,24 @@ public:
          */
         kSkipDraw_BlendOptFlag          = 0x1,
         /**
-         * Emit the src color, disable HW blending (replace dst with src)
-         */
-        kDisableBlend_BlendOptFlag      = 0x2,
-        /**
          * The coverage value does not have to be computed separately from alpha, the the output
          * color can be the modulation of the two.
          */
-        kCoverageAsAlpha_BlendOptFlag   = 0x4,
+        kCoverageAsAlpha_BlendOptFlag   = 0x2,
         /**
          * Instead of emitting a src color, emit coverage in the alpha channel and r,g,b are
          * "don't cares".
          */
-        kEmitCoverage_BlendOptFlag      = 0x8,
+        kEmitCoverage_BlendOptFlag      = 0x4,
         /**
          * Emit transparent black instead of the src color, no need to compute coverage.
          */
-        kEmitTransBlack_BlendOptFlag    = 0x10,
+        kEmitTransBlack_BlendOptFlag    = 0x8,
         /**
          * Flag used to invalidate the cached BlendOptFlags, OptSrcCoeff, and OptDstCoeff cached by
          * the get BlendOpts function. 
          */
-        kInvalid_BlendOptFlag        = 0x20,
+        kInvalid_BlendOptFlag           = 1 << 31,
     };
     GR_DECL_BITFIELD_OPS_FRIENDS(BlendOptFlags);