Use SkMScalar as intermediates in SkMatrix44::setConcat.

src/utils/SkMatrix44.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMatrix44.h"
 
 static inline bool eq4(const SkMScalar* SK_RESTRICT a,
@@ skipping 365 matching lines @@
         result[6] = result[7] = result[8] = result[9] = 0;
         result[10] = a.fMat[2][2] * b.fMat[2][2];
         result[11] = 0;
         result[12] = a.fMat[0][0] * b.fMat[3][0] + a.fMat[3][0];
         result[13] = a.fMat[1][1] * b.fMat[3][1] + a.fMat[3][1];
         result[14] = a.fMat[2][2] * b.fMat[3][2] + a.fMat[3][2];
         result[15] = 1;
     } else {
         for (int j = 0; j < 4; j++) {
             for (int i = 0; i < 4; i++) {
-                double value = 0;
+                SkMScalar value = 0;
                 for (int k = 0; k < 4; k++) {
-                    value += SkMScalarToDouble(a.fMat[k][i]) * b.fMat[j][k];
+                    value += a.fMat[k][i] * b.fMat[j][k];
                 }
-                *result++ = SkDoubleToMScalar(value);
+                *result++ = value;
             }
         }
     }
 
     if (useStorage) {
         memcpy(fMat, storage, sizeof(storage));
     }
     this->dirtyTypeMask();
 }
 
@@ skipping 522 matching lines @@
     dst[SkMatrix::kMSkewY]  = SkMScalarToScalar(fMat[0][1]);
     dst[SkMatrix::kMScaleY] = SkMScalarToScalar(fMat[1][1]);
     dst[SkMatrix::kMTransY] = SkMScalarToScalar(fMat[3][1]);
 
     dst[SkMatrix::kMPersp0] = SkMScalarToScalar(fMat[0][3]);
     dst[SkMatrix::kMPersp1] = SkMScalarToScalar(fMat[1][3]);
     dst[SkMatrix::kMPersp2] = SkMScalarToScalar(fMat[3][3]);
 
     return dst;
 }