Ensure that NativeViewport destructs correctly on Linux.

components/native_viewport/native_viewport_impl.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 COMPONENTS_NATIVE_VIEWPORT_NATIVE_VIEWPORT_IMPL_H_
 #define COMPONENTS_NATIVE_VIEWPORT_NATIVE_VIEWPORT_IMPL_H_
 
 #include <set>
 
 #include "base/macros.h"
@@ skipping 52 matching lines @@
   void OnConnectionError() override;
 
  private:
   // Callback when the dispatcher has processed a message we're waiting on
   // an ack from. |pointer_id| identifies the pointer the message was associated
   // with.
   void AckEvent(int32 pointer_id);
 
   bool is_headless_;
   scoped_ptr<PlatformViewport> platform_viewport_;
-  OnscreenContextProvider context_provider_;
+  scoped_ptr<OnscreenContextProvider> context_provider_;
   bool sent_metrics_;
   mojo::ViewportMetricsPtr metrics_;
   CreateCallback create_callback_;
   RequestMetricsCallback metrics_callback_;
   mojo::NativeViewportEventDispatcherPtr event_dispatcher_;
   mojo::Binding<mojo::NativeViewport> binding_;
 
   // Set of pointer_ids we've sent a move to and are waiting on an ack.
   std::set<int32> pointers_waiting_on_ack_;
 
   base::WeakPtrFactory<NativeViewportImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewportImpl);
 };
 
 }  // namespace native_viewport
 
 #endif  // COMPONENTS_NATIVE_VIEWPORT_NATIVE_VIEWPORT_IMPL_H_