cc: Change TODO into comment.

cc/resources/picture_layer_tiling_set.cc

 // 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.
 
 #include "cc/resources/picture_layer_tiling_set.h"
 
 #include <limits>
 
 namespace cc {
 
@@ skipping 316 matching lines @@
 
 size_t PictureLayerTilingSet::GPUMemoryUsageInBytes() const {
   size_t amount = 0;
   for (size_t i = 0; i < tilings_.size(); ++i)
     amount += tilings_[i]->GPUMemoryUsageInBytes();
   return amount;
 }
 
 PictureLayerTilingSet::TilingRange PictureLayerTilingSet::GetTilingRange(
     TilingRangeType type) const {
-  // TODO(reveman): Compute these ranges only when the tiling set has changed
-  // instead of each time GetTilingRange() is called.
+  // Doesn't seem to be the case right now but if it ever becomes a performance
+  // problem to compute these ranges each time this function is called, we can
+  // compute them only when the tiling set has changed instead.
   TilingRange high_res_range(0, 0);
   TilingRange low_res_range(tilings_.size(), tilings_.size());
   for (size_t i = 0; i < tilings_.size(); ++i) {
     const PictureLayerTiling* tiling = tilings_[i];
     if (tiling->resolution() == HIGH_RESOLUTION)
       high_res_range = TilingRange(i, i + 1);
     if (tiling->resolution() == LOW_RESOLUTION)
       low_res_range = TilingRange(i, i + 1);
   }
 
   switch (type) {
     case HIGHER_THAN_HIGH_RES:
       return TilingRange(0, high_res_range.start);
     case HIGH_RES:
       return high_res_range;
     case BETWEEN_HIGH_AND_LOW_RES:
       return TilingRange(high_res_range.end, low_res_range.start);
     case LOW_RES:
       return low_res_range;
     case LOWER_THAN_LOW_RES:
       return TilingRange(low_res_range.end, tilings_.size());
   }
 
   NOTREACHED();
   return TilingRange(0, 0);
 }
 
 }  // namespace cc