Update from https://crrev.com/306655

cc/resources/tile.h

 // Copyright 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 CC_RESOURCES_TILE_H_
 #define CC_RESOURCES_TILE_H_
 
 #include "base/memory/ref_counted.h"
 #include "cc/base/ref_counted_managed.h"
 #include "cc/resources/managed_tile_state.h"
 #include "cc/resources/raster_source.h"
 #include "cc/resources/tile_priority.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace cc {
 
+class TileManager;
+
 class CC_EXPORT Tile : public RefCountedManaged<Tile> {
  public:
   enum TileRasterFlags { USE_PICTURE_ANALYSIS = 1 << 0 };
 
   typedef uint64 Id;
 
   Id id() const {
     return id_;
   }
 
@@ skipping 154 matching lines @@
 
   Id id_;
   static Id s_next_id_;
 
   DISALLOW_COPY_AND_ASSIGN(Tile);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TILE_H_