Remove base::NonThreadSafe now that all users are gone!!

content/browser/compositor/browser_compositor_output_surface.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_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 #define CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
 #include "build/build_config.h"
 #include "cc/output/output_surface.h"
 #include "content/common/content_export.h"
 
 namespace cc {
 class SoftwareOutputDevice;
 }
 
 namespace viz {
 class CompositorOverlayCandidateValidator;
@@ skipping 52 matching lines @@
  private:
   std::unique_ptr<viz::CompositorOverlayCandidateValidator>
       overlay_candidate_validator_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserCompositorOutputSurface);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_