Replace deprecated base::NonThreadSafe in /content/renderer/gpu in favor of ThreadChecker.

content/renderer/gpu/compositor_external_begin_frame_source.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_RENDERER_GPU_COMPOSITOR_EXTERNAL_BEGIN_FRAME_SOURCE_H_
 #define CONTENT_RENDERER_GPU_COMPOSITOR_EXTERNAL_BEGIN_FRAME_SOURCE_H_
 
 #include <unordered_set>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/threading/thread_checker.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "content/renderer/gpu/compositor_forwarding_message_filter.h"
 
 namespace IPC {
 class Message;
 class SyncMessageFilter;
 }
 
 namespace content {
 
 // This class can be created only on the main thread, but then becomes pinned
 // to a fixed thread where cc::Scheduler is running.
 //
 // TODO(enne): This only implements the BeginFrameSource interface to
 // make it easier to give to cc as an external begin frame source.  In the
 // future, if this is owned by an output surface, then the internal
 // cc::ExternalBeginFrameSource can be the BeginFrameSource passed to cc
 // directly rather than proxied by this class.
 class CompositorExternalBeginFrameSource
     : public cc::BeginFrameSource,
-      public cc::ExternalBeginFrameSourceClient,
-      public NON_EXPORTED_BASE(base::NonThreadSafe) {
+      public cc::ExternalBeginFrameSourceClient {
  public:
   explicit CompositorExternalBeginFrameSource(
       CompositorForwardingMessageFilter* filter,
       IPC::SyncMessageFilter* sync_message_filter,
       int routing_id);
   ~CompositorExternalBeginFrameSource() override;
 
   // cc::BeginFrameSource implementation.
   void AddObserver(cc::BeginFrameObserver* obs) override;
   void RemoveObserver(cc::BeginFrameObserver* obs) override;
@@ skipping 35 matching lines @@
   // Shared helper implementation.
   cc::ExternalBeginFrameSource external_begin_frame_source_;
 
   scoped_refptr<CompositorForwardingMessageFilter> begin_frame_source_filter_;
   scoped_refptr<CompositorExternalBeginFrameSourceProxy>
       begin_frame_source_proxy_;
   scoped_refptr<IPC::SyncMessageFilter> message_sender_;
   int routing_id_;
   CompositorForwardingMessageFilter::Handler begin_frame_source_filter_handler_;
 
+  THREAD_CHECKER(thread_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(CompositorExternalBeginFrameSource);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_COMPOSITOR_EXTERNAL_BEGIN_FRAME_SOURCE_H_