Move code that doesn't depend on PPAPI out of remoting/client/plugin

remoting/client/plugin/empty_cursor_filter.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 REMOTING_CLIENT_PLUGIN_EMPTY_CURSOR_FILTER_H_
-#define REMOTING_CLIENT_PLUGIN_EMPTY_CURSOR_FILTER_H_
-
-#include "remoting/protocol/cursor_shape_stub.h"
-
-namespace remoting {
-
-// Returns an empty cursor.
-protocol::CursorShapeInfo EmptyCursorShape();
-
-// Returns true of the supplied cursor is empty, i.e. width and/or height <= 0.
-bool IsCursorShapeEmpty(const protocol::CursorShapeInfo& cursor_shape);
-
-// Helper that checks whether a cursor has any visible pixels, and resizes
-// it down to (0x0) if not.
-// TODO(wez): Turn this into a general-purpose cropping filter that both
-// client and host can use.
-class EmptyCursorFilter : public protocol::CursorShapeStub {
- public:
-  explicit EmptyCursorFilter(protocol::CursorShapeStub* cursor_stub);
-  ~EmptyCursorFilter() override;
-
-  // protocol::CursorShapeStub interface.
-  void SetCursorShape(const protocol::CursorShapeInfo& cursor_shape) override;
-
-  // Replaces the stub to which cursor shapes will be passed-on.
-  void set_cursor_stub(protocol::CursorShapeStub* cursor_stub) {
-    cursor_stub_ = cursor_stub;
-  }
-
- private:
-  protocol::CursorShapeStub* cursor_stub_;
-
-  DISALLOW_COPY_AND_ASSIGN(EmptyCursorFilter);
-};
-
-}  // namespace remoting
-
-#endif  // REMOTING_CLIENT_PLUGIN_EMPTY_CURSOR_FILTER_H_