Clear IOSurfaces immediately after creating them.

ui/gfx/mac/io_surface.cc

 // Copyright 2015 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 "ui/gfx/mac/io_surface.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/logging.h"
@@ skipping 130 matching lines @@
   AddIntegerValue(properties, kIOSurfaceWidth, size.width());
   AddIntegerValue(properties, kIOSurfaceHeight, size.height());
   AddIntegerValue(properties, kIOSurfacePixelFormat, PixelFormat(format));
   if (num_planes > 1) {
     CFDictionaryAddValue(properties, kIOSurfacePlaneInfo, planes);
   } else {
     AddIntegerValue(properties, kIOSurfaceBytesPerElement,
                     BytesPerElement(format, 0));
   }
 
-  return IOSurfaceCreate(properties);
+  IOSurfaceRef surface = IOSurfaceCreate(properties);
+
+  // Zero-initialize the IOSurface. Calling IOSurfaceLock/IOSurfaceUnlock
+  // appears to be sufficient.
+  // https://code.google.com/p/chromium/issues/detail?id=584760#c17

[Avi (use Gerrit), 2016/02/17 23:07:25]

You can abbreviate it as

https://crbug.com/584760#c17

and put it on the previous line.

[erikchen, 2016/02/17 23:55:30]

Done.

+  IOReturn r = IOSurfaceLock(surface, 0, nullptr);
+  DCHECK_EQ(kIOReturnSuccess, r);
+  r = IOSurfaceUnlock(surface, 0, nullptr);
+  DCHECK_EQ(kIOReturnSuccess, r);
+
+  return surface;
 }
 
 }  // namespace gfx