cc: Add PictureLayerTilingSet to manage PictureLayerTiling

cc/picture_layer_tiling_set.h

Index: cc/picture_layer_tiling_set.h
diff --git a/cc/picture_layer_tiling_set.h b/cc/picture_layer_tiling_set.h
new file mode 100644
index 0000000000000000000000000000000000000000..d302125b4a1f980357a26165e3ccaf552de3a8d5
--- /dev/null
+++ b/cc/picture_layer_tiling_set.h
@@ -0,0 +1,76 @@
+// 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_PICTURE_LAYER_TILING_SET_H_
+#define CC_PICTURE_LAYER_TILING_SET_H_
+
+#include "cc/picture_layer_tiling.h"
+#include "cc/region.h"
+#include "cc/scoped_ptr_vector.h"
+#include "ui/gfx/size.h"
+
+namespace cc {
+
+class CC_EXPORT PictureLayerTilingSet {
+ public:
+  PictureLayerTilingSet(PictureLayerTilingClient* client);
+  ~PictureLayerTilingSet();
+
+  // Shallow copies all data (except client) from other.
+  void CloneFrom(const PictureLayerTilingSet& other);
+
+  void SetLayerBounds(gfx::Size layer_bounds);
+  gfx::Size LayerBounds() const;
+
+  void Invalidate(const Region& invalidation);
+
+  void AddTiling(float contents_scale, gfx::Size tile_size);
+  size_t num_tilings() const { return tilings_.size(); }
+
+  // For a given rect, iterates through tiles that can fill it.  If no
+  // set of tiles with resources can fill the rect, then it will iterate
+  // through null tiles with valid geometry_rect() until the rect is full.
+  // If all tiles have resources, the union of all geometry_rects will
+  // exactly fill rect with no overlap.
+  class CC_EXPORT Iterator {
+   public:
+    Iterator(PictureLayerTilingSet* set, float contents_scale, gfx::Rect rect);
+    ~Iterator();
+
+    // Visible rect (no borders), always in the space of rect,
+    // regardless of the relative contents scale of the tiling.
+    gfx::Rect geometry_rect() const;
+    // Texture rect (in texels) for geometry_rect
+    gfx::RectF texture_rect() const;
+    // Texture size in texels
+    gfx::Size texture_size() const;
+
+    Tile* operator->() const;
+    Tile* operator*() const;
+
+    Iterator& operator++();
+    operator bool() const;
+
+   private:
+    PictureLayerTilingSet* set_;
+    float contents_scale_;
+    PictureLayerTiling::Iterator tiling_iter_;
+    int current_tiling_;
+
+    Region current_region_;
+    Region missing_region_;
+    Region::Iterator region_iter_;
+  };
+
+ private:
+  PictureLayerTilingClient* client_;
+  gfx::Size layer_bounds_;
+  ScopedPtrVector<PictureLayerTiling> tilings_;
+
+  friend class Iterator;
+};
+
+}  // namespace cc
+
+#endif  // CC_PICTURE_LAYER_TILING_SET_H_