cc: Clean up DisplayItemList API

cc/playback/display_item_list.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 CC_PLAYBACK_DISPLAY_ITEM_LIST_H_
 #define CC_PLAYBACK_DISPLAY_ITEM_LIST_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 58 matching lines @@
   // retain_individual_display_items_ is false. This method also updates
   // approximate_op_count_.
   void RasterIntoCanvas(const DisplayItem& display_item);
 
   // Because processing happens in this function, all the set up for
   // this item should be done via the args, which is why the return
   // type needs to be const, to prevent set-after-processing mistakes.
   template <typename DisplayItemType, typename... Args>
   const DisplayItemType& CreateAndAppendItem(const gfx::Rect& visual_rect,
                                              Args&&... args) {
-    visual_rects_.push_back(visual_rect);
-    auto* item = &items_.AllocateAndConstruct<DisplayItemType>(
+    inputs_.visual_rects.push_back(visual_rect);
+    auto* item = &inputs_.items.AllocateAndConstruct<DisplayItemType>(
         std::forward<Args>(args)...);
     approximate_op_count_ += item->ApproximateOpCount();
     ProcessAppendedItem(item);
     return *item;
   }
 
   // Called after all items are appended, to process the items and, if
   // applicable, create an internally cached SkPicture.
   void Finalize();
 
   void SetIsSuitableForGpuRasterization(bool is_suitable) {
-    is_suitable_for_gpu_rasterization_ = is_suitable;
+    inputs_.is_suitable_for_gpu_rasterization = is_suitable;
   }
   bool IsSuitableForGpuRasterization() const;
   int ApproximateOpCount() const;
   size_t ApproximateMemoryUsage() const;
   bool ShouldBeAnalyzedForSolidColor() const;
 
   bool RetainsIndividualDisplayItems() const;
 
   std::unique_ptr<base::trace_event::ConvertableToTraceFormat> AsValue(
       bool include_items) const;
 
   void EmitTraceSnapshot() const;
 
   void GenerateDiscardableImagesMetadata();
   void GetDiscardableImagesInRect(const gfx::Rect& rect,
                                   float raster_scale,
                                   std::vector<DrawImage>* images);
 
-  gfx::Rect VisualRectForTesting(int index) { return visual_rects_[index]; }
+  gfx::Rect VisualRectForTesting(int index) {
+    return inputs_.visual_rects[index];
+  }
 
   ContiguousContainer<DisplayItem>::const_iterator begin() const {
-    return items_.begin();
+    return inputs_.items.begin();
   }
 
   ContiguousContainer<DisplayItem>::const_iterator end() const {
-    return items_.end();
+    return inputs_.items.end();
   }
 
  private:
   DisplayItemList(gfx::Rect layer_rect,
                   const DisplayItemListSettings& display_list_settings,
                   bool retain_individual_display_items);
   ~DisplayItemList();
 
   void ProcessAppendedItem(const DisplayItem* item);
 
-  ContiguousContainer<DisplayItem> items_;
-  // The visual rects associated with each of the display items in the
-  // display item list. There is one rect per display item, and the
-  // position in |visual_rects_| matches the position of the item in
-  // |items_| . These rects are intentionally kept separate
-  // because they are not needed while walking the |items_| for raster.
-  std::vector<gfx::Rect> visual_rects_;
   sk_sp<SkPicture> picture_;
 
   std::unique_ptr<SkPictureRecorder> recorder_;
-  const DisplayItemListSettings settings_;
+
   bool retain_individual_display_items_;
-
-  gfx::Rect layer_rect_;
-  bool is_suitable_for_gpu_rasterization_;
   int approximate_op_count_;
 
   // Memory usage due to the cached SkPicture.
   size_t picture_memory_usage_;
 
   DiscardableImageMap image_map_;
 
+  struct Inputs {
+    Inputs(gfx::Rect layer_rect, const DisplayItemListSettings& settings);
+    ~Inputs();
+
+    ContiguousContainer<DisplayItem> items;
+    // The visual rects associated with each of the display items in the
+    // display item list. There is one rect per display item, and the
+    // position in |visual_rects| matches the position of the item in
+    // |items| . These rects are intentionally kept separate
+    // because they are not needed while walking the |items| for raster.
+    std::vector<gfx::Rect> visual_rects;
+
+    const DisplayItemListSettings settings;
+    gfx::Rect layer_rect;
+    bool is_suitable_for_gpu_rasterization;
+  };
+
+  Inputs inputs_;
+
   friend class base::RefCountedThreadSafe<DisplayItemList>;
   FRIEND_TEST_ALL_PREFIXES(DisplayItemListTest, ApproximateMemoryUsage);
   DISALLOW_COPY_AND_ASSIGN(DisplayItemList);
 };
 
 }  // namespace cc
 
 #endif  // CC_PLAYBACK_DISPLAY_ITEM_LIST_H_