Implements core logic for Pixel Canvas

ui/compositor/paint_context.h

 // Copyright 2015 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_COMPOSITOR_PAINT_CONTEXT_H_
 #define UI_COMPOSITOR_PAINT_CONTEXT_H_
 
 #include <memory>
 
 #include "base/logging.h"
@@ skipping 28 matching lines @@
     CLONE_WITHOUT_INVALIDATION,
   };
   PaintContext(const PaintContext& other, CloneWithoutInvalidation c);
 
   ~PaintContext();
 
   // When true, IsRectInvalid() can be called, otherwise its result would be
   // invalid.
   bool CanCheckInvalid() const { return !invalidation_.IsEmpty(); }
 
+  float device_scale_factor() const { return device_scale_factor_; }
+
   // When true, the |bounds| touches an invalidated area, so should be
   // re-painted. When false, re-painting can be skipped. Bounds should be in
   // the local space with offsets up to the painting root in the PaintContext.
   bool IsRectInvalid(const gfx::Rect& bounds) const {
     DCHECK(CanCheckInvalid());
     return invalidation_.Intersects(bounds + offset_);
   }
 
 #if DCHECK_IS_ON()
   void Visited(void* visited) const {
@@ skipping 44 matching lines @@
   // recorder is active.
   mutable bool inside_paint_recorder_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(PaintContext);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_PAINT_CONTEXT_H_