cc: Add tiling raster tile iterators.

cc/base/tiling_data.cc

 // Copyright 2010 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.
 
 #include "cc/base/tiling_data.h"
 
 #include <algorithm>
 
 #include "ui/gfx/rect.h"
 #include "ui/gfx/vector2d.h"
@@ skipping 254 matching lines @@
   num_tiles_y_ = ComputeNumTiles(
       max_texture_size_.height(), total_size_.height(), border_texels_);
 }
 
 TilingData::BaseIterator::BaseIterator(const TilingData* tiling_data)
     : tiling_data_(tiling_data),
       index_x_(-1),
       index_y_(-1) {
 }
 
+TilingData::Iterator::Iterator() : BaseIterator(NULL) { done(); }
+
 TilingData::Iterator::Iterator(const TilingData* tiling_data,
                                const gfx::Rect& tiling_rect)
     : BaseIterator(tiling_data),
       left_(-1),
       right_(-1),
       bottom_(-1) {
   if (tiling_data_->num_tiles_x() <= 0 || tiling_data_->num_tiles_y() <= 0) {
     done();
     return;
   }
@@ skipping 117 matching lines @@
       }
     }
 
     if (index_y_ > consider_bottom_)
       done();
   }
 
   return *this;
 }
 
+TilingData::SpiralDifferenceIterator::SpiralDifferenceIterator()
+    : BaseIterator(NULL) {
+  done();
+}
+
 TilingData::SpiralDifferenceIterator::SpiralDifferenceIterator(
     const TilingData* tiling_data,
     const gfx::Rect& consider_rect,
     const gfx::Rect& ignore_rect,
     const gfx::Rect& center_rect)
     : BaseIterator(tiling_data),
       consider_left_(-1),
       consider_top_(-1),
       consider_right_(-1),
       consider_bottom_(-1),
@@ skipping 207 matching lines @@
   current_step_ = 0;
   direction_ = static_cast<Direction>((direction_ + 1) % 4);
 
   if (direction_ == RIGHT || direction_ == LEFT) {
     ++vertical_step_count_;
     ++horizontal_step_count_;
   }
 }
 
 }  // namespace cc