Remove unused in-process pepper APIs

ppapi/cpp/dev/scrollbar_dev.h

-// Copyright (c) 2010 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 PPAPI_CPP_DEV_SCROLLBAR_DEV_H_
-#define PPAPI_CPP_DEV_SCROLLBAR_DEV_H_
-
-#include "ppapi/c/dev/ppb_scrollbar_dev.h"
-#include "ppapi/cpp/dev/widget_dev.h"
-
-namespace pp {
-
-class InstanceHandle;
-
-// This class allows a plugin to use the browser's scrollbar widget.
-class Scrollbar_Dev : public Widget_Dev {
- public:
-  // Creates an is_null() Scrollbar object.
-  Scrollbar_Dev() {}
-
-  explicit Scrollbar_Dev(PP_Resource resource);
-  Scrollbar_Dev(const InstanceHandle& instance, bool vertical);
-  Scrollbar_Dev(const Scrollbar_Dev& other);
-
-  Scrollbar_Dev& operator=(const Scrollbar_Dev& other);
-
-  // PPB_Scrollbar methods:
-  uint32_t GetThickness();
-  bool IsOverlay();
-  uint32_t GetValue();
-  void SetValue(uint32_t value);
-  void SetDocumentSize(uint32_t size);
-  void SetTickMarks(const Rect* tick_marks, uint32_t count);
-  void ScrollBy(PP_ScrollBy_Dev unit, int32_t multiplier);
-};
-
-}  // namespace pp
-
-#endif  // PPAPI_CPP_DEV_SCROLLBAR_DEV_H_