In SkPixmap.cpp, change SkAlphaMul to SkMulDiv255.

src/core/SkPixmap.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorPriv.h"
 #include "SkConfig8888.h"
 #include "SkMask.h"
@@ skipping 145 matching lines @@
             }
             break;
         }
         case kARGB_4444_SkColorType:
         case kRGB_565_SkColorType: {
             uint16_t* p = this->writable_addr16(area.fLeft, area.fTop);
             uint16_t v;
             
             // make rgb premultiplied
             if (255 != a) {
-                r = SkAlphaMul(r, a);
-                g = SkAlphaMul(g, a);
-                b = SkAlphaMul(b, a);
+                r = SkMulDiv255Round(r, a);
+                g = SkMulDiv255Round(g, a);
+                b = SkMulDiv255Round(b, a);
             }
             
             if (kARGB_4444_SkColorType == this->colorType()) {
                 v = pack_8888_to_4444(a, r, g, b);
             } else {
                 v = SkPackRGB16(r >> (8 - SK_R16_BITS),
                                 g >> (8 - SK_G16_BITS),
                                 b >> (8 - SK_B16_BITS));
             }
             while (--height >= 0) {
                 sk_memset16(p, v, width);
                 p = (uint16_t*)((char*)p + rowBytes);
             }
             break;
         }
         case kBGRA_8888_SkColorType:
         case kRGBA_8888_SkColorType: {
             uint32_t* p = this->writable_addr32(area.fLeft, area.fTop);
             
             if (255 != a && kPremul_SkAlphaType == this->alphaType()) {
-                r = SkAlphaMul(r, a);
-                g = SkAlphaMul(g, a);
-                b = SkAlphaMul(b, a);
+                r = SkMulDiv255Round(r, a);
+                g = SkMulDiv255Round(g, a);
+                b = SkMulDiv255Round(b, a);
             }
-            uint32_t v = kRGBA_8888_SkColorType == this->colorType() ?
-            SkPackARGB_as_RGBA(a, r, g, b) : SkPackARGB_as_BGRA(a, r, g, b);
-            
+            uint32_t v = kRGBA_8888_SkColorType == this->colorType()
+                             ? SkPackARGB_as_RGBA(a, r, g, b)
+                             : SkPackARGB_as_BGRA(a, r, g, b);
+
             while (--height >= 0) {
                 sk_memset32(p, v, width);
                 p = (uint32_t*)((char*)p + rowBytes);
             }
             break;
         }
         default:
             return false; // no change, so don't call notifyPixelsChanged()
     }
     return true;
@@ skipping 58 matching lines @@
     this->reset(info, pixels, rb);
     fStorage = pixels;
     return true;
 }
 
 void SkAutoPixmapStorage::alloc(const SkImageInfo& info) {
     if (!this->tryAlloc(info)) {
         sk_throw();
     }
 }