Implements core logic for Pixel Canvas

cc/paint/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_PAINT_DISPLAY_ITEM_LIST_H_
 #define CC_PAINT_DISPLAY_ITEM_LIST_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 120 matching lines @@
   }
 
   bool HasDiscardableImages() const {
     return paint_op_buffer_.HasDiscardableImages();
   }
 
   // Generate a PaintRecord from this DisplayItemList, leaving |this| in
   // an empty state.
   sk_sp<PaintRecord> ReleaseAsRecord();
 
+  bool pixel_canvas_enabled() const { return pixel_canvas_enabled_; }
+  void set_pixel_canvas_enabled(bool value) { pixel_canvas_enabled_ = value; }
+
  private:
   FRIEND_TEST_ALL_PREFIXES(DisplayItemListTest, AsValueWithNoOps);
   FRIEND_TEST_ALL_PREFIXES(DisplayItemListTest, AsValueWithOps);
 
   ~DisplayItemList();
 
   void Reset();
 
   std::unique_ptr<base::trace_event::TracedValue> CreateTracedValue(
       bool include_items) const;
@@ skipping 20 matching lines @@
   size_t current_range_start_ = 0;
   // For debugging, tracks the number of currently nested visual rects being
   // added.
   int in_paired_begin_count_ = 0;
   // For debugging, tracks if we're painting a visual rect range, to prevent
   // nesting.
   bool in_painting_ = false;
 
   size_t op_count_ = 0u;
 
+  // Set true if we are using pixel canvas. This mode allows us to records all
+  // canvas draw commands in pixel aligned measurements and scale elements using
+  // the corner points.
+  bool pixel_canvas_enabled_ = false;
+
   friend class base::RefCountedThreadSafe<DisplayItemList>;
   FRIEND_TEST_ALL_PREFIXES(DisplayItemListTest, BytesUsed);
   DISALLOW_COPY_AND_ASSIGN(DisplayItemList);
 };
 
 }  // namespace cc
 
 #endif  // CC_PAINT_DISPLAY_ITEM_LIST_H_