Fix custom cursor transparency compositing on MacOS

content/common/cursors/webcursor_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/cursors/webcursor.h"
 
 #import <AppKit/AppKit.h>
 
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
@@ skipping 133 matching lines @@
   }
 
   // If the size is empty, use a 1x1 transparent image.
   gfx::Size size = custom_size;
   if (size.IsEmpty()) {
     size.SetSize(1, 1);
     data = NULL;
   }
 
   SkBitmap bitmap;
-  if (bitmap.tryAllocN32Pixels(size.width(), size.height()) && data)
+  SkImageInfo image_info = SkImageInfo::MakeN32(size.width(), size.height(),
+                                                kUnpremul_SkAlphaType);
+  if (bitmap.tryAllocPixels(image_info) && data)
     memcpy(bitmap.getAddr32(0, 0), data, data_size);
   else
     bitmap.eraseARGB(0, 0, 0, 0);
 
   // Convert from pixels to view units.
   if (custom_scale == 0)
     custom_scale = 1;
   NSSize dip_size = NSSizeFromCGSize(
       gfx::ScaleToFlooredSize(custom_size, 1 / custom_scale).ToCGSize());
   NSPoint dip_hotspot = NSPointFromCGPoint(gfx::ToFlooredPoint(
@@ skipping 214 matching lines @@
 
 void WebCursor::CleanupPlatformData() {
   return;
 }
 
 void WebCursor::CopyPlatformData(const WebCursor& other) {
   return;
 }
 
 }  // namespace content