Two malloc+bzero -> calloc.

src/image/SkSurface_Raster.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkSurface_Base.h"
 #include "SkImagePriv.h"
 #include "SkCanvas.h"
@@ skipping 81 matching lines @@
 }
 
 SkSurface_Raster::SkSurface_Raster(SkPixelRef* pr, const SkSurfaceProps* props)
     : INHERITED(pr->info().width(), pr->info().height(), props)
 {
     const SkImageInfo& info = pr->info();
 
     fBitmap.setInfo(info, info.minRowBytes());
     fBitmap.setPixelRef(pr);
     fWeOwnThePixels = true;
-
-    if (!info.isOpaque()) {
-        fBitmap.eraseColor(SK_ColorTRANSPARENT);
-    }
 }
 
 SkCanvas* SkSurface_Raster::onNewCanvas() { return new SkCanvas(fBitmap, this->props()); }
 
 SkSurface* SkSurface_Raster::onNewSurface(const SkImageInfo& info) {
     return SkSurface::NewRaster(info, &this->props());
 }
 
 void SkSurface_Raster::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
                               const SkPaint* paint) {
@@ skipping 49 matching lines @@
     if (nullptr == releaseProc) {
         context = nullptr;
     }
     if (!SkSurface_Raster::Valid(info, rb)) {
         return nullptr;
     }
     if (nullptr == pixels) {
         return nullptr;
     }
 
     return new SkSurface_Raster(info, pixels, rb, releaseProc, context, props);

[reed1, 2015/12/31 13:17:49]

When the constructor is called from here, do we know that the caller has zeroed
the pixels?

[mtklein, 2015/12/31 21:35:47]

There are two constructors.  This CL only changes the 2-argument constructor
used below when we own the pixels.
It does not change the 6-argument constructor used here for unowned pixels
(which has never zeroed the pixels).

 }
 
 SkSurface* SkSurface::NewRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes,
                                       const SkSurfaceProps* props) {
     return NewRasterDirectReleaseProc(info, pixels, rowBytes, nullptr, nullptr, props);
 }
 
 SkSurface* SkSurface::NewRaster(const SkImageInfo& info, const SkSurfaceProps* props) {
     if (!SkSurface_Raster::Valid(info)) {
         return nullptr;
     }
 
-    SkAutoTUnref<SkPixelRef> pr(SkMallocPixelRef::NewAllocate(info, 0, nullptr));
+    SkAutoTUnref<SkPixelRef> pr(SkMallocPixelRef::NewZeroed(info, 0, nullptr));
     if (nullptr == pr.get()) {
         return nullptr;
     }
     return new SkSurface_Raster(pr, props);
 }