content: Cleanup class/struct forward declarations

content/renderer/bluetooth/web_bluetooth_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 CONTENT_RENDERER_BLUETOOTH_WEB_BLUETOOTH_IMPL_H_
 #define CONTENT_RENDERER_BLUETOOTH_WEB_BLUETOOTH_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 15 matching lines @@
 class WebBluetoothRemoteGATTCharacteristic;
 }
 
 namespace service_manager {
 class InterfaceProvider;
 }
 
 namespace content {
 
 class BluetoothDispatcher;
-class ThreadSafeSender;
 
 // Implementation of blink::WebBluetooth. Passes calls through to the thread
 // specific BluetoothDispatcher.
 class CONTENT_EXPORT WebBluetoothImpl
     : NON_EXPORTED_BASE(public blink::mojom::WebBluetoothServiceClient),
       NON_EXPORTED_BASE(public blink::WebBluetooth) {
  public:
   WebBluetoothImpl(service_manager::InterfaceProvider* remote_interfaces);
   ~WebBluetoothImpl() override;
 
@@ skipping 103 matching lines @@
 
   // Binding associated with |web_bluetooth_service_|.
   mojo::AssociatedBinding<blink::mojom::WebBluetoothServiceClient> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(WebBluetoothImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_BLUETOOTH_WEB_BLUETOOTH_IMPL_H_