Revert of Change call-sites now that SkCanvas is not ref-counted

content/browser/compositor/software_output_device_mac.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_BROWSER_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_MAC_H_
 #define CONTENT_BROWSER_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_MAC_H_
 
 #include <IOSurface/IOSurface.h>
 
 #include "base/mac/scoped_cftyperef.h"
@@ skipping 48 matching lines @@
   // and the index of the current buffer is |current_buffer_|.
   base::ScopedCFTypeRef<IOSurfaceRef> io_surfaces_[2];
   int current_index_;
 
   // The previous frame's damage rectangle. Used to copy unchanged content
   // between buffers in CopyPreviousBufferDamage.
   SkRegion previous_buffer_damage_region_;
 
   // The SkCanvas wrapps the mapped current IOSurface. It is valid only between
   // BeginPaint and EndPaint.
-  std::unique_ptr<SkCanvas> canvas_;
+  sk_sp<SkCanvas> canvas_;
 
   gfx::VSyncProvider::UpdateVSyncCallback update_vsync_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SoftwareOutputDeviceMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_MAC_H_