Make gMask_00FF00FF a constant

src/core/SkBlitMask_D32.cpp

 #include "SkBlitMask.h"
 #include "SkColor.h"
 #include "SkColorPriv.h"
 
 static void D32_A8_Color(void* SK_RESTRICT dst, size_t dstRB,
                          const void* SK_RESTRICT maskPtr, size_t maskRB,
                          SkColor color, int width, int height) {
     SkPMColor pmc = SkPreMultiplyColor(color);
     size_t dstOffset = dstRB - (width << 2);
     size_t maskOffset = maskRB - width;
@@ skipping 335 matching lines @@
 // instead of
 // expand..combine add expand..combine
 //
 #define EXPAND0(v, m, s)    ((v) & (m)) * (s)
 #define EXPAND1(v, m, s)    (((v) >> 8) & (m)) * (s)
 #define COMBINE(e0, e1, m)  ((((e0) >> 8) & (m)) | ((e1) & ~(m)))
 
 static void A8_RowProc_Opaque(SkPMColor* SK_RESTRICT dst,
                               const uint8_t* SK_RESTRICT mask,
                               const SkPMColor* SK_RESTRICT src, int count) {
-#if 0 // suppress warning
-    const uint32_t rbmask = gMask_00FF00FF;
-#endif
     for (int i = 0; i < count; ++i) {
         int m = mask[i];
         if (m) {
             m += (m >> 7);
 #if 1
             // this is slightly slower than the expand/combine version, but it
             // is much closer to the old results, so we use it for now to reduce
             // rebaselining.
             dst[i] = SkAlphaMulQ(src[i], m) + SkAlphaMulQ(dst[i], 256 - m);
 #else
@@ skipping 214 matching lines @@
             if (flags & kSrcIsOpaque_RowFlag) {
                 index |= 1;
             }
             SkASSERT((size_t)index < SK_ARRAY_COUNT(gProcs));
             return gProcs[index];
         default:
             break;
     }
     return NULL;
 }