Tidy up ChromotingInstance members a little.

remoting/protocol/mouse_input_filter.h

 // Copyright (c) 2012 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 REMOTING_PROTOCOL_MOUSE_INPUT_FILTER_H_
 #define REMOTING_PROTOCOL_MOUSE_INPUT_FILTER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "remoting/protocol/input_filter.h"
 #include "remoting/protocol/input_stub.h"
 #include "third_party/skia/include/core/SkTypes.h"
 #include "third_party/skia/include/core/SkSize.h"
 
 namespace remoting {
 namespace protocol {
 
 // Filtering InputStub implementation which scales mouse events based on the
 // supplied input and output dimensions, and clamps their coordinates to the
 // output dimensions, before passing events on to |input_stub|.
 class MouseInputFilter : public InputFilter {
  public:
+  MouseInputFilter();
   explicit MouseInputFilter(InputStub* input_stub);
   virtual ~MouseInputFilter();
 
   // Specify the input dimensions for mouse events.
   void set_input_size(const SkISize& size);
 
   // Specify the output dimensions.
   void set_output_size(const SkISize& size);
 
   // InputStub overrides.
   virtual void InjectMouseEvent(const protocol::MouseEvent& event) OVERRIDE;
 
  private:
   SkISize input_max_;
   SkISize output_max_;
 
   DISALLOW_COPY_AND_ASSIGN(MouseInputFilter);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_MOUSE_INPUT_FILTER_H_