Making CursorFactoryOzone thread-local

ui/base/cursor/cursor_loader_ozone.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_BASE_CURSOR_CURSOR_LOADER_OZONE_H_
 #define UI_BASE_CURSOR_CURSOR_LOADER_OZONE_H_
 
 #include <map>
 
 #include "base/macros.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/base/cursor/cursor_loader.h"
 
 namespace ui {
 
+class CursorFactoryOzone;
+
 class UI_BASE_EXPORT CursorLoaderOzone : public CursorLoader {
  public:
+  // CursorLoaderOzone will use CursorFactoryOzone corresponding to the thread
+  // it was constructed on.
   CursorLoaderOzone();
   ~CursorLoaderOzone() override;
 
   // CursorLoader overrides:
   void LoadImageCursor(CursorType id,
                        int resource_id,
                        const gfx::Point& hot) override;
   void LoadAnimatedCursor(CursorType id,
                           int resource_id,
                           const gfx::Point& hot,
                           int frame_delay_ms) override;
   void UnloadAll() override;
   void SetPlatformCursor(gfx::NativeCursor* cursor) override;
 
  private:
   // Pointers are owned by ResourceBundle and must not be freed here.
   typedef std::map<CursorType, PlatformCursor> ImageCursorMap;
   ImageCursorMap cursors_;
+  CursorFactoryOzone* factory_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(CursorLoaderOzone);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_CURSOR_CURSOR_LOADER_OZONE_H_