Make tile size a function of the device scale factor.

cc/layers/picture_layer_impl.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_LAYERS_PICTURE_LAYER_IMPL_H_
 #define CC_LAYERS_PICTURE_LAYER_IMPL_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 11 matching lines @@
 namespace cc {
 
 struct AppendQuadsData;
 class MicroBenchmarkImpl;
 class Tile;
 
 class CC_EXPORT PictureLayerImpl
     : public LayerImpl,
       NON_EXPORTED_BASE(public PictureLayerTilingClient) {
  public:
+  // TODO(crbug.com/622885): This should scale with the device scale factor.
+  enum : int { kMaxUntiledContentSize = 512 };
+
   static std::unique_ptr<PictureLayerImpl> Create(LayerTreeImpl* tree_impl,
                                                   int id,
                                                   bool is_mask) {
     return base::WrapUnique(new PictureLayerImpl(tree_impl, id, is_mask));
   }
   ~PictureLayerImpl() override;
 
   bool is_mask() const { return is_mask_; }
 
   // LayerImpl overrides.
@@ skipping 118 matching lines @@
   // of comparing pointers, since objects pointed to are not guaranteed to
   // exist.
   std::vector<PictureLayerTiling*> last_append_quads_tilings_;
 
   DISALLOW_COPY_AND_ASSIGN(PictureLayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_IMPL_H_