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

content/browser/compositor/software_output_device_win.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_WIN_H_
 #define CONTENT_BROWSER_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_WIN_H_
 
 #include <stddef.h>
 #include <windows.h>
 
@@ skipping 45 matching lines @@
   void Resize(const gfx::Size& viewport_pixel_size,
               float scale_factor) override;
   SkCanvas* BeginPaint(const gfx::Rect& damage_rect) override;
   void EndPaint() override;
 
   gfx::Size viewport_pixel_size() const { return viewport_pixel_size_; }
   void ReleaseContents();
 
  private:
   HWND hwnd_;
-  std::unique_ptr<SkCanvas> contents_;
+  sk_sp<SkCanvas> contents_;
   bool is_hwnd_composited_;
   OutputDeviceBacking* backing_;
   bool in_paint_;
 
   DISALLOW_COPY_AND_ASSIGN(SoftwareOutputDeviceWin);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_SOFTWARE_OUTPUT_DEVICE_WIN_H_