Ozone: Remove the caca platform from the tree

ui/ozone/platform/caca/caca_event_source.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 UI_OZONE_PLATFORM_CACA_CACA_EVENT_SOURCE_H_
-#define UI_OZONE_PLATFORM_CACA_CACA_EVENT_SOURCE_H_
-
-#include <caca.h>
-
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/time/time.h"
-#include "ui/events/platform/platform_event_source.h"
-#include "ui/events/platform/scoped_event_dispatcher.h"
-#include "ui/gfx/geometry/point_f.h"
-
-namespace ui {
-
-class CacaWindow;
-
-class CacaEventSource : public PlatformEventSource {
- public:
-  CacaEventSource();
-  ~CacaEventSource() override;
-
-  // Poll for an event on a particular window. Input events will be
-  // dispatched on the given dispatcher.
-  void TryProcessingEvent(CacaWindow* window);
-
-  // Process an input event on a particular window.
-  void OnInputEvent(caca_event_t* event, CacaWindow* window);
-
- private:
-  // Keep track of last cursor position to dispatch correct mouse push/release
-  // events.
-  gfx::PointF last_cursor_location_;
-
-  int modifier_flags_ = 0;
-
-  DISALLOW_COPY_AND_ASSIGN(CacaEventSource);
-};
-
-}  // namespace ui
-
-#endif  // UI_OZONE_PLATFORM_CACA_CACA_EVENT_SOURCE_H_