Revert "Revert of https://codereview.chromium.org/108773003/"

src/effects/gradients/SkGradientShader.cpp

Index: src/effects/gradients/SkGradientShader.cpp
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 27761993461ba7761a8afc57c36eac9ec2754cc4..5d200d18d354135f7f11e4807964631edc32409e 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -513,13 +513,14 @@ const uint16_t* SkGradientShaderBase::getCache16() const {
 
 const SkPMColor* SkGradientShaderBase::getCache32() const {
     if (fCache32 == NULL) {
-        // double the count for dither entries
-        const int entryCount = kCache32Count * 4;
-        const size_t allocSize = sizeof(SkPMColor) * entryCount;
+        SkImageInfo info;
+        info.fWidth = kCache32Count;
+        info.fHeight = 4;   // for our 4 dither rows
+        info.fAlphaType = kPremul_SkAlphaType;
+        info.fColorType = kPMColor_SkColorType;
 
         if (NULL == fCache32PixelRef) {
-            fCache32PixelRef = SkNEW_ARGS(SkMallocPixelRef,
-                                          (NULL, allocSize, NULL));
+            fCache32PixelRef = SkMallocPixelRef::NewAllocate(info, 0, NULL);
         }
         fCache32 = (SkPMColor*)fCache32PixelRef->getAddr();
         if (fColorCount == 2) {
@@ -541,8 +542,7 @@ const SkPMColor* SkGradientShaderBase::getCache32() const {
         }
 
         if (fMapper) {
-            SkMallocPixelRef* newPR = SkNEW_ARGS(SkMallocPixelRef,
-                                                 (NULL, allocSize, NULL));
+            SkMallocPixelRef* newPR = SkMallocPixelRef::NewAllocate(info, 0, NULL);
             SkPMColor* linear = fCache32;           // just computed linear data
             SkPMColor* mapped = (SkPMColor*)newPR->getAddr();    // storage for mapped data
             SkUnitMapper* map = fMapper;