Makes tile-creation lazy

cc/resources/tile.h

Index: cc/resources/tile.h
diff --git a/cc/resources/tile.h b/cc/resources/tile.h
index 904eb0ba8409de2bcd3d4627689b5f84379098f8..6382cbd9499681cee6fb01c0d6744e92edd76b00 100644
--- a/cc/resources/tile.h
+++ b/cc/resources/tile.h
@@ -27,6 +27,7 @@ class CC_EXPORT Tile : public base::RefCounted<Tile> {
        gfx::Size tile_size,
        GLenum format,
        gfx::Rect content_rect,
+       gfx::Rect paint_rect,
        gfx::Rect opaque_rect,
        float contents_scale,
        int layer_id);
@@ -59,6 +60,7 @@ class CC_EXPORT Tile : public base::RefCounted<Tile> {
 
   float contents_scale() const { return contents_scale_; }
   gfx::Rect content_rect() const { return content_rect_; }
+  gfx::Rect paint_rect() const { return paint_rect_; }
 
   int layer_id() const { return layer_id_; }
 
@@ -89,6 +91,7 @@ class CC_EXPORT Tile : public base::RefCounted<Tile> {
   gfx::Rect tile_size_;
   GLenum format_;
   gfx::Rect content_rect_;
+  gfx::Rect paint_rect_;

[enne (OOO), 2013/03/27 22:15:39]

As a follow-up to whunt's offline question about storing paint_rect instead of
content_rect here, I don't think that's possible.  Two tilings can share the
same tile using the same picture pile but have different paint rects (because
the layer size shrank, for example).  Between paint rect and content rect, the
content rect of the tile is the constant shared piece of information between
both tilings using that tile.

   float contents_scale_;
   gfx::Rect opaque_rect_;