cc: Merge LayerTree into the LayerTreeHost.

cc/layers/layer.h

 // Copyright 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 CC_LAYERS_LAYER_H_
 #define CC_LAYERS_LAYER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <set>
 #include <string>
 #include <unordered_map>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/region.h"
 #include "cc/debug/micro_benchmark.h"
 #include "cc/input/input_handler.h"
 #include "cc/layers/layer_collections.h"
 #include "cc/layers/layer_position_constraint.h"
 #include "cc/layers/paint_properties.h"
 #include "cc/output/filter_operations.h"
 #include "cc/trees/element_id.h"
-#include "cc/trees/layer_tree.h"
 #include "cc/trees/mutator_host_client.h"
 #include "cc/trees/property_tree.h"
 #include "cc/trees/target_property.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkPicture.h"
 #include "ui/gfx/geometry/point3_f.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/geometry/scroll_offset.h"
 #include "ui/gfx/transform.h"
@@ skipping 279 matching lines @@
   TakeDebugInfo();
   virtual void didUpdateMainThreadScrollingReasons();
 
   void SetLayerClient(LayerClient* client) { inputs_.client = client; }
 
   virtual bool IsSnapped();
 
   virtual void PushPropertiesTo(LayerImpl* layer);
 
   LayerTreeHost* GetLayerTreeHostForTesting() const { return layer_tree_host_; }
-  LayerTree* GetLayerTree() const;
 
   virtual ScrollbarLayerInterface* ToScrollbarLayer();
 
   virtual sk_sp<SkPicture> GetPicture() const;
 
   // Constructs a LayerImpl of the correct runtime type for this Layer type.
   virtual std::unique_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
 
   bool NeedsDisplayForTesting() const { return !inputs_.update_rect.IsEmpty(); }
   void ResetNeedsDisplayForTesting() { inputs_.update_rect = gfx::Rect(); }
@@ skipping 94 matching lines @@
   void ClearPreferredRasterBounds();
 
   MutatorHost* GetMutatorHost() const;
 
   ElementListType GetElementTypeForAnimation() const;
 
   void SetScrollbarsHiddenFromImplSide(bool hidden);
 
   const gfx::Rect& update_rect() const { return inputs_.update_rect; }
 
+  LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }

[danakj, 2017/01/27 17:25:09]

There used to be this:

   LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
   const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }

Is the const one never needed, there's no const Layers running around? If you
had to work around the missing const one anywhere can you add it here instead?

[Khushal, 2017/01/27 18:52:19]

Nah, I don't think the const one is used anymore. I just added this one and no
errors.

+
  protected:
   friend class LayerImpl;
   friend class TreeSynchronizer;
   virtual ~Layer();
   Layer();
 
-  LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
-
   // These SetNeeds functions are in order of severity of update:
   //
   // Called when this layer has been modified in some way, but isn't sure
   // that it needs a commit yet.  It needs CalcDrawProperties and UpdateLayers
   // before it knows whether or not a commit is required.
   void SetNeedsUpdate();
   // Called when a property has been modified in a way that the layer
   // knows immediately that a commit is required.  This implies SetNeedsUpdate
   // as well as SetNeedsPushProperties to push that property.
   void SetNeedsCommit();
@@ skipping 19 matching lines @@
 
   bool IsPropertyChangeAllowed() const;
 
   // When true, the layer is about to perform an update. Any commit requests
   // will be handled implicitly after the update completes.
   bool ignore_set_needs_commit_;
 
  private:
   friend class base::RefCounted<Layer>;
   friend class LayerTreeHostCommon;
-  friend class LayerTree;
+  friend class LayerTreeHost;
   friend class LayerInternalsForTest;
 
   // Interactions with attached animations.
   gfx::ScrollOffset ScrollOffsetForAnimation() const;
   void OnFilterAnimated(const FilterOperations& filters);
   void OnOpacityAnimated(float opacity);
   void OnTransformAnimated(const gfx::Transform& transform);
   void OnScrollOffsetAnimated(const gfx::ScrollOffset& scroll_offset);
 
   void OnIsAnimatingChanged(const PropertyAnimationState& mask,
@@ skipping 119 matching lines @@
 
     gfx::Size preferred_raster_bounds;
   };
 
   Layer* parent_;
 
   // Layer instances have a weak pointer to their LayerTreeHost.
   // This pointer value is nil when a Layer is not in a tree and is
   // updated via SetLayerTreeHost() if a layer moves between trees.
   LayerTreeHost* layer_tree_host_;
-  LayerTree* layer_tree_;
 
   Inputs inputs_;
 
   int num_descendants_that_draw_content_;
   int transform_tree_index_;
   int effect_tree_index_;
   int clip_tree_index_;
   int scroll_tree_index_;
   int property_tree_sequence_number_;
   gfx::Vector2dF offset_to_transform_parent_;
@@ skipping 17 matching lines @@
   // These all act like draw properties, so don't need push properties.
   gfx::Rect visible_layer_rect_;
   size_t num_unclipped_descendants_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_