cc/tiles/tiling_set_eviction_queue.cc - chromium/src - Git at Google

 // Copyright 2014 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 <utility>

 #include "cc/tiles/tiling_set_eviction_queue.h"

 namespace cc {

 TilingSetEvictionQueue::TilingSetEvictionQueue(
     PictureLayerTilingSet* tiling_set)
     : tree_(tiling_set->tree()), phase_(EVENTUALLY_RECT) {
   // Early out if the layer has no tilings.
   if (!tiling_set->num_tilings())
     return;
   GenerateTilingOrder(tiling_set);
   eventually_iterator_ = EventuallyTilingIterator(&tilings_, tree_);
   if (eventually_iterator_.done()) {
     AdvancePhase();
     return;
   }
   current_tile_ = *eventually_iterator_;
 }

 TilingSetEvictionQueue::~TilingSetEvictionQueue() {
 }

 void TilingSetEvictionQueue::GenerateTilingOrder(
     PictureLayerTilingSet* tiling_set) {
   tilings_.reserve(tiling_set->num_tilings());
   // Generate all of the tilings in the order described in the header comment
   // for this class.
   PictureLayerTilingSet::TilingRange range =
       tiling_set->GetTilingRange(PictureLayerTilingSet::HIGHER_THAN_HIGH_RES);
   for (size_t index = range.start; index < range.end; ++index) {
     PictureLayerTiling* tiling = tiling_set->tiling_at(index);
     if (tiling->has_tiles())
       tilings_.push_back(tiling);
   }

   range = tiling_set->GetTilingRange(PictureLayerTilingSet::LOWER_THAN_LOW_RES);
   for (size_t i = range.start; i < range.end; ++i) {
     size_t index = range.start + (range.end - 1 - i);
     PictureLayerTiling* tiling = tiling_set->tiling_at(index);
     if (tiling->has_tiles())
       tilings_.push_back(tiling);
   }

   range = tiling_set->GetTilingRange(
       PictureLayerTilingSet::BETWEEN_HIGH_AND_LOW_RES);
   for (size_t i = range.start; i < range.end; ++i) {
     size_t index = range.start + (range.end - 1 - i);
     PictureLayerTiling* tiling = tiling_set->tiling_at(index);
     if (tiling->has_tiles())
       tilings_.push_back(tiling);
   }

   range = tiling_set->GetTilingRange(PictureLayerTilingSet::LOW_RES);
   for (size_t index = range.start; index < range.end; ++index) {
     PictureLayerTiling* tiling = tiling_set->tiling_at(index);
     if (tiling->has_tiles())
       tilings_.push_back(tiling);
   }

   range = tiling_set->GetTilingRange(PictureLayerTilingSet::HIGH_RES);
   for (size_t index = range.start; index < range.end; ++index) {
     PictureLayerTiling* tiling = tiling_set->tiling_at(index);
     if (tiling->has_tiles())
       tilings_.push_back(tiling);
   }
   DCHECK_GE(tiling_set->num_tilings(), tilings_.size());
 }

 void TilingSetEvictionQueue::AdvancePhase() {
   current_tile_ = PrioritizedTile();
   while (!current_tile_.tile() &&
          phase_ != VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_UNOCCLUDED) {
     phase_ = static_cast<Phase>(phase_ + 1);
     switch (phase_) {
       case EVENTUALLY_RECT:
         NOTREACHED();
         break;
       case SOON_BORDER_RECT:
         soon_iterator_ = SoonBorderTilingIterator(&tilings_, tree_);
         if (!soon_iterator_.done())
           current_tile_ = *soon_iterator_;
         break;
       case SKEWPORT_RECT:
         skewport_iterator_ = SkewportTilingIterator(&tilings_, tree_);
         if (!skewport_iterator_.done())
           current_tile_ = *skewport_iterator_;
         break;
       case PENDING_VISIBLE_RECT:
         pending_visible_iterator_ = PendingVisibleTilingIterator(
             &tilings_, tree_, false /* return required for activation tiles */);
         if (!pending_visible_iterator_.done())
           current_tile_ = *pending_visible_iterator_;
         break;
       case PENDING_VISIBLE_RECT_REQUIRED_FOR_ACTIVATION:
         pending_visible_iterator_ = PendingVisibleTilingIterator(
             &tilings_, tree_, true /* return required for activation tiles */);
         if (!pending_visible_iterator_.done())
           current_tile_ = *pending_visible_iterator_;
         break;
       case VISIBLE_RECT_OCCLUDED:
         visible_iterator_ = VisibleTilingIterator(
             &tilings_, tree_, true /* return occluded tiles */,
             false /* return required for activation tiles */);
         if (!visible_iterator_.done())
           current_tile_ = *visible_iterator_;
         break;
       case VISIBLE_RECT_UNOCCLUDED:
         visible_iterator_ = VisibleTilingIterator(
             &tilings_, tree_, false /* return occluded tiles */,
             false /* return required for activation tiles */);
         if (!visible_iterator_.done())
           current_tile_ = *visible_iterator_;
         break;
       case VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_OCCLUDED:
         visible_iterator_ = VisibleTilingIterator(
             &tilings_, tree_, true /* return occluded tiles */,
             true /* return required for activation tiles */);
         if (!visible_iterator_.done())
           current_tile_ = *visible_iterator_;
         break;
       case VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_UNOCCLUDED:
         visible_iterator_ = VisibleTilingIterator(
             &tilings_, tree_, false /* return occluded tiles */,
             true /* return required for activation tiles */);
         if (!visible_iterator_.done())
           current_tile_ = *visible_iterator_;
         break;
     }
   }
 }

 bool TilingSetEvictionQueue::IsEmpty() const {
   return !current_tile_.tile();
 }

 const PrioritizedTile& TilingSetEvictionQueue::Top() const {
   DCHECK(!IsEmpty());
   return current_tile_;
 }

 void TilingSetEvictionQueue::Pop() {
   DCHECK(!IsEmpty());
   current_tile_ = PrioritizedTile();
   switch (phase_) {
     case EVENTUALLY_RECT:
       ++eventually_iterator_;
       if (!eventually_iterator_.done())
         current_tile_ = *eventually_iterator_;
       break;
     case SOON_BORDER_RECT:
       ++soon_iterator_;
       if (!soon_iterator_.done())
         current_tile_ = *soon_iterator_;
       break;
     case SKEWPORT_RECT:
       ++skewport_iterator_;
       if (!skewport_iterator_.done())
         current_tile_ = *skewport_iterator_;
       break;
     case PENDING_VISIBLE_RECT:
     case PENDING_VISIBLE_RECT_REQUIRED_FOR_ACTIVATION:
       ++pending_visible_iterator_;
       if (!pending_visible_iterator_.done())
         current_tile_ = *pending_visible_iterator_;
       break;
     case VISIBLE_RECT_OCCLUDED:
     case VISIBLE_RECT_UNOCCLUDED:
     case VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_OCCLUDED:
     case VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_UNOCCLUDED:
       ++visible_iterator_;
       if (!visible_iterator_.done())
         current_tile_ = *visible_iterator_;
       break;
   }
   if (!current_tile_.tile())
     AdvancePhase();
 }

 // EvictionRectIterator
 TilingSetEvictionQueue::EvictionRectIterator::EvictionRectIterator()
     : tilings_(nullptr), tree_(ACTIVE_TREE), tiling_index_(0) {
 }

 TilingSetEvictionQueue::EvictionRectIterator::EvictionRectIterator(
     std::vector<PictureLayerTiling*>* tilings,
     WhichTree tree,
     PictureLayerTiling::PriorityRectType priority_rect_type)
     : tilings_(tilings),
       tree_(tree),
       priority_rect_type_(priority_rect_type),
       tiling_index_(0) {
 }

 template <typename TilingIteratorType>
 bool TilingSetEvictionQueue::EvictionRectIterator::AdvanceToNextTile(
     TilingIteratorType* iterator) {
   bool found_tile = false;
   while (!found_tile) {
     ++(*iterator);
     if (!(*iterator)) {
       prioritized_tile_ = PrioritizedTile();
       break;
     }
     found_tile = GetFirstTileAndCheckIfValid(iterator);
   }
   return found_tile;
 }

 template <typename TilingIteratorType>
 bool TilingSetEvictionQueue::EvictionRectIterator::GetFirstTileAndCheckIfValid(
     TilingIteratorType* iterator) {
   PictureLayerTiling* tiling = (*tilings_)[tiling_index_];
   Tile* tile = tiling->TileAt(iterator->index_x(), iterator->index_y());
   prioritized_tile_ = PrioritizedTile();
   // If there's nothing to evict, return false.
   if (!tile || !tile->draw_info().has_resource())
     return false;
   // After the pending visible rect has been processed, we must return false
   // for pending visible rect tiles as tiling iterators do not ignore those
   // tiles.
   if (priority_rect_type_ > PictureLayerTiling::PENDING_VISIBLE_RECT) {
     gfx::Rect tile_rect = tiling->tiling_data()->TileBounds(
         tile->tiling_i_index(), tile->tiling_j_index());
     if (tiling->pending_visible_rect().Intersects(tile_rect))
       return false;
   }
   (*tilings_)[tiling_index_]->UpdateRequiredStatesOnTile(tile);
   prioritized_tile_ = (*tilings_)[tiling_index_]->MakePrioritizedTile(
       tile, priority_rect_type_);
   // In other cases, the tile we got is a viable candidate, return true.
   return true;
 }

 // EventuallyTilingIterator
 TilingSetEvictionQueue::EventuallyTilingIterator::EventuallyTilingIterator(
     std::vector<PictureLayerTiling*>* tilings,
     WhichTree tree)
     : EvictionRectIterator(tilings, tree, PictureLayerTiling::EVENTUALLY_RECT) {
   // Find the first tiling with a tile.
   while (tiling_index_ < tilings_->size()) {
     if (!(*tilings_)[tiling_index_]->has_eventually_rect_tiles()) {
       ++tiling_index_;
       continue;
     }
     iterator_ = TilingData::ReverseSpiralDifferenceIterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->current_eventually_rect(),
         (*tilings_)[tiling_index_]->current_skewport_rect(),
         (*tilings_)[tiling_index_]->current_soon_border_rect());
     if (!iterator_) {
       ++tiling_index_;
       continue;
     }
     break;
   }
   if (tiling_index_ >= tilings_->size())
     return;
   if (!GetFirstTileAndCheckIfValid(&iterator_))
     ++(*this);
 }

 TilingSetEvictionQueue::EventuallyTilingIterator&
     TilingSetEvictionQueue::EventuallyTilingIterator::
     operator++() {
   bool found_tile = AdvanceToNextTile(&iterator_);
   while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
     ++tiling_index_;
     if (!(*tilings_)[tiling_index_]->has_eventually_rect_tiles())
       continue;
     iterator_ = TilingData::ReverseSpiralDifferenceIterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->current_eventually_rect(),
         (*tilings_)[tiling_index_]->current_skewport_rect(),
         (*tilings_)[tiling_index_]->current_soon_border_rect());
     if (!iterator_)
       continue;
     found_tile = GetFirstTileAndCheckIfValid(&iterator_);
     if (!found_tile)
       found_tile = AdvanceToNextTile(&iterator_);
   }
   return *this;
 }

 // SoonBorderTilingIterator
 TilingSetEvictionQueue::SoonBorderTilingIterator::SoonBorderTilingIterator(
     std::vector<PictureLayerTiling*>* tilings,
     WhichTree tree)
     : EvictionRectIterator(tilings,
                            tree,
                            PictureLayerTiling::SOON_BORDER_RECT) {
   // Find the first tiling with a tile.
   while (tiling_index_ < tilings_->size()) {
     if (!(*tilings_)[tiling_index_]->has_soon_border_rect_tiles()) {
       ++tiling_index_;
       continue;
     }
     iterator_ = TilingData::ReverseSpiralDifferenceIterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->current_soon_border_rect(),
         (*tilings_)[tiling_index_]->current_skewport_rect(),
         (*tilings_)[tiling_index_]->current_visible_rect());
     if (!iterator_) {
       ++tiling_index_;
       continue;
     }
     break;
   }
   if (tiling_index_ >= tilings_->size())
     return;
   if (!GetFirstTileAndCheckIfValid(&iterator_))
     ++(*this);
 }

 TilingSetEvictionQueue::SoonBorderTilingIterator&
     TilingSetEvictionQueue::SoonBorderTilingIterator::
     operator++() {
   bool found_tile = AdvanceToNextTile(&iterator_);
   while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
     ++tiling_index_;
     if (!(*tilings_)[tiling_index_]->has_soon_border_rect_tiles())
       continue;
     iterator_ = TilingData::ReverseSpiralDifferenceIterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->current_soon_border_rect(),
         (*tilings_)[tiling_index_]->current_skewport_rect(),
         (*tilings_)[tiling_index_]->current_visible_rect());
     if (!iterator_)
       continue;
     found_tile = GetFirstTileAndCheckIfValid(&iterator_);
     if (!found_tile)
       found_tile = AdvanceToNextTile(&iterator_);
   }
   return *this;
 }

 // SkewportTilingIterator
 TilingSetEvictionQueue::SkewportTilingIterator::SkewportTilingIterator(
     std::vector<PictureLayerTiling*>* tilings,
     WhichTree tree)
     : EvictionRectIterator(tilings, tree, PictureLayerTiling::SKEWPORT_RECT) {
   // Find the first tiling with a tile.
   while (tiling_index_ < tilings_->size()) {
     if (!(*tilings_)[tiling_index_]->has_skewport_rect_tiles()) {
       ++tiling_index_;
       continue;
     }
     iterator_ = TilingData::ReverseSpiralDifferenceIterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->current_skewport_rect(),
         (*tilings_)[tiling_index_]->current_visible_rect(),
         (*tilings_)[tiling_index_]->current_visible_rect());
     if (!iterator_) {
       ++tiling_index_;
       continue;
     }
     break;
   }
   if (tiling_index_ >= tilings_->size())
     return;
   if (!GetFirstTileAndCheckIfValid(&iterator_))
     ++(*this);
 }

 TilingSetEvictionQueue::SkewportTilingIterator&
     TilingSetEvictionQueue::SkewportTilingIterator::
     operator++() {
   bool found_tile = AdvanceToNextTile(&iterator_);
   while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
     ++tiling_index_;
     if (!(*tilings_)[tiling_index_]->has_skewport_rect_tiles())
       continue;
     iterator_ = TilingData::ReverseSpiralDifferenceIterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->current_skewport_rect(),
         (*tilings_)[tiling_index_]->current_visible_rect(),
         (*tilings_)[tiling_index_]->current_visible_rect());
     if (!iterator_)
       continue;
     found_tile = GetFirstTileAndCheckIfValid(&iterator_);
     if (!found_tile)
       found_tile = AdvanceToNextTile(&iterator_);
   }
   return *this;
 }

 // PendingVisibleIterator
 TilingSetEvictionQueue::PendingVisibleTilingIterator::
     PendingVisibleTilingIterator(std::vector<PictureLayerTiling*>* tilings,
                                  WhichTree tree,
                                  bool return_required_for_activation_tiles)
     : EvictionRectIterator(tilings,
                            tree,
                            PictureLayerTiling::PENDING_VISIBLE_RECT),
       return_required_for_activation_tiles_(
           return_required_for_activation_tiles) {
   // Find the first tiling with a tile.
   while (tiling_index_ < tilings_->size()) {
     iterator_ = TilingData::DifferenceIterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->pending_visible_rect(),
         (*tilings_)[tiling_index_]->current_visible_rect());
     if (!iterator_) {
       ++tiling_index_;
       continue;
     }
     break;
   }
   if (tiling_index_ >= tilings_->size())
     return;
   if (!GetFirstTileAndCheckIfValid(&iterator_)) {
     ++(*this);
     return;
   }
   if (!TileMatchesRequiredFlags(prioritized_tile_)) {
     ++(*this);
     return;
   }
 }

 TilingSetEvictionQueue::PendingVisibleTilingIterator&
     TilingSetEvictionQueue::PendingVisibleTilingIterator::
     operator++() {
   bool found_tile = AdvanceToNextTile(&iterator_);
   while (found_tile && !TileMatchesRequiredFlags(prioritized_tile_))
     found_tile = AdvanceToNextTile(&iterator_);

   while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
     ++tiling_index_;
     iterator_ = TilingData::DifferenceIterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->pending_visible_rect(),
         (*tilings_)[tiling_index_]->current_visible_rect());
     if (!iterator_)
       continue;
     found_tile = GetFirstTileAndCheckIfValid(&iterator_);
     if (!found_tile)
       found_tile = AdvanceToNextTile(&iterator_);
     while (found_tile && !TileMatchesRequiredFlags(prioritized_tile_))
       found_tile = AdvanceToNextTile(&iterator_);
   }
   return *this;
 }

 bool TilingSetEvictionQueue::PendingVisibleTilingIterator::
     TileMatchesRequiredFlags(const PrioritizedTile& tile) const {
   bool activation_flag_matches = tile.tile()->required_for_activation() ==
                                  return_required_for_activation_tiles_;
   return activation_flag_matches;
 }

 // VisibleTilingIterator
 TilingSetEvictionQueue::VisibleTilingIterator::VisibleTilingIterator(
     std::vector<PictureLayerTiling*>* tilings,
     WhichTree tree,
     bool return_occluded_tiles,
     bool return_required_for_activation_tiles)
     : EvictionRectIterator(tilings, tree, PictureLayerTiling::VISIBLE_RECT),
       return_occluded_tiles_(return_occluded_tiles),
       return_required_for_activation_tiles_(
           return_required_for_activation_tiles) {
   // Find the first tiling with a tile.
   while (tiling_index_ < tilings_->size()) {
     if (!(*tilings_)[tiling_index_]->has_visible_rect_tiles()) {
       ++tiling_index_;
       continue;
     }
     iterator_ = TilingData::Iterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->current_visible_rect(), false);
     if (!iterator_) {
       ++tiling_index_;
       continue;
     }
     break;
   }
   if (tiling_index_ >= tilings_->size())
     return;
   if (!GetFirstTileAndCheckIfValid(&iterator_)) {
     ++(*this);
     return;
   }
   if (!TileMatchesRequiredFlags(prioritized_tile_)) {
     ++(*this);
     return;
   }
 }

 TilingSetEvictionQueue::VisibleTilingIterator&
     TilingSetEvictionQueue::VisibleTilingIterator::
     operator++() {
   bool found_tile = AdvanceToNextTile(&iterator_);
   while (found_tile && !TileMatchesRequiredFlags(prioritized_tile_))
     found_tile = AdvanceToNextTile(&iterator_);

   while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
     ++tiling_index_;
     if (!(*tilings_)[tiling_index_]->has_visible_rect_tiles())
       continue;
     iterator_ = TilingData::Iterator(
         (*tilings_)[tiling_index_]->tiling_data(),
         (*tilings_)[tiling_index_]->current_visible_rect(), false);
     if (!iterator_)
       continue;
     found_tile = GetFirstTileAndCheckIfValid(&iterator_);
     if (!found_tile)
       found_tile = AdvanceToNextTile(&iterator_);
     while (found_tile && !TileMatchesRequiredFlags(prioritized_tile_))
       found_tile = AdvanceToNextTile(&iterator_);
   }
   return *this;
 }

 bool TilingSetEvictionQueue::VisibleTilingIterator::TileMatchesRequiredFlags(
     const PrioritizedTile& tile) const {
   bool activation_flag_matches = tile.tile()->required_for_activation() ==
                                  return_required_for_activation_tiles_;
   bool occluded_flag_matches = tile.is_occluded() == return_occluded_tiles_;
   return activation_flag_matches && occluded_flag_matches;
 }

 }  // namespace cc
	// Copyright 2014 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 <utility>

	#include "cc/tiles/tiling_set_eviction_queue.h"

	namespace cc {

	TilingSetEvictionQueue::TilingSetEvictionQueue(
	PictureLayerTilingSet* tiling_set)
	: tree_(tiling_set->tree()), phase_(EVENTUALLY_RECT) {
	// Early out if the layer has no tilings.
	if (!tiling_set->num_tilings())
	return;
	GenerateTilingOrder(tiling_set);
	eventually_iterator_ = EventuallyTilingIterator(&tilings_, tree_);
	if (eventually_iterator_.done()) {
	AdvancePhase();
	return;
	}
	current_tile_ = *eventually_iterator_;
	}

	TilingSetEvictionQueue::~TilingSetEvictionQueue() {
	}

	void TilingSetEvictionQueue::GenerateTilingOrder(
	PictureLayerTilingSet* tiling_set) {
	tilings_.reserve(tiling_set->num_tilings());
	// Generate all of the tilings in the order described in the header comment
	// for this class.
	PictureLayerTilingSet::TilingRange range =
	tiling_set->GetTilingRange(PictureLayerTilingSet::HIGHER_THAN_HIGH_RES);
	for (size_t index = range.start; index < range.end; ++index) {
	PictureLayerTiling* tiling = tiling_set->tiling_at(index);
	if (tiling->has_tiles())
	tilings_.push_back(tiling);
	}

	range = tiling_set->GetTilingRange(PictureLayerTilingSet::LOWER_THAN_LOW_RES);
	for (size_t i = range.start; i < range.end; ++i) {
	size_t index = range.start + (range.end - 1 - i);
	PictureLayerTiling* tiling = tiling_set->tiling_at(index);
	if (tiling->has_tiles())
	tilings_.push_back(tiling);
	}

	range = tiling_set->GetTilingRange(
	PictureLayerTilingSet::BETWEEN_HIGH_AND_LOW_RES);
	for (size_t i = range.start; i < range.end; ++i) {
	size_t index = range.start + (range.end - 1 - i);
	PictureLayerTiling* tiling = tiling_set->tiling_at(index);
	if (tiling->has_tiles())
	tilings_.push_back(tiling);
	}

	range = tiling_set->GetTilingRange(PictureLayerTilingSet::LOW_RES);
	for (size_t index = range.start; index < range.end; ++index) {
	PictureLayerTiling* tiling = tiling_set->tiling_at(index);
	if (tiling->has_tiles())
	tilings_.push_back(tiling);
	}

	range = tiling_set->GetTilingRange(PictureLayerTilingSet::HIGH_RES);
	for (size_t index = range.start; index < range.end; ++index) {
	PictureLayerTiling* tiling = tiling_set->tiling_at(index);
	if (tiling->has_tiles())
	tilings_.push_back(tiling);
	}
	DCHECK_GE(tiling_set->num_tilings(), tilings_.size());
	}

	void TilingSetEvictionQueue::AdvancePhase() {
	current_tile_ = PrioritizedTile();
	while (!current_tile_.tile() &&
	phase_ != VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_UNOCCLUDED) {
	phase_ = static_cast<Phase>(phase_ + 1);
	switch (phase_) {
	case EVENTUALLY_RECT:
	NOTREACHED();
	break;
	case SOON_BORDER_RECT:
	soon_iterator_ = SoonBorderTilingIterator(&tilings_, tree_);
	if (!soon_iterator_.done())
	current_tile_ = *soon_iterator_;
	break;
	case SKEWPORT_RECT:
	skewport_iterator_ = SkewportTilingIterator(&tilings_, tree_);
	if (!skewport_iterator_.done())
	current_tile_ = *skewport_iterator_;
	break;
	case PENDING_VISIBLE_RECT:
	pending_visible_iterator_ = PendingVisibleTilingIterator(
	&tilings_, tree_, false /* return required for activation tiles */);
	if (!pending_visible_iterator_.done())
	current_tile_ = *pending_visible_iterator_;
	break;
	case PENDING_VISIBLE_RECT_REQUIRED_FOR_ACTIVATION:
	pending_visible_iterator_ = PendingVisibleTilingIterator(
	&tilings_, tree_, true /* return required for activation tiles */);
	if (!pending_visible_iterator_.done())
	current_tile_ = *pending_visible_iterator_;
	break;
	case VISIBLE_RECT_OCCLUDED:
	visible_iterator_ = VisibleTilingIterator(
	&tilings_, tree_, true /* return occluded tiles */,
	false /* return required for activation tiles */);
	if (!visible_iterator_.done())
	current_tile_ = *visible_iterator_;
	break;
	case VISIBLE_RECT_UNOCCLUDED:
	visible_iterator_ = VisibleTilingIterator(
	&tilings_, tree_, false /* return occluded tiles */,
	false /* return required for activation tiles */);
	if (!visible_iterator_.done())
	current_tile_ = *visible_iterator_;
	break;
	case VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_OCCLUDED:
	visible_iterator_ = VisibleTilingIterator(
	&tilings_, tree_, true /* return occluded tiles */,
	true /* return required for activation tiles */);
	if (!visible_iterator_.done())
	current_tile_ = *visible_iterator_;
	break;
	case VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_UNOCCLUDED:
	visible_iterator_ = VisibleTilingIterator(
	&tilings_, tree_, false /* return occluded tiles */,
	true /* return required for activation tiles */);
	if (!visible_iterator_.done())
	current_tile_ = *visible_iterator_;
	break;
	}
	}
	}

	bool TilingSetEvictionQueue::IsEmpty() const {
	return !current_tile_.tile();
	}

	const PrioritizedTile& TilingSetEvictionQueue::Top() const {
	DCHECK(!IsEmpty());
	return current_tile_;
	}

	void TilingSetEvictionQueue::Pop() {
	DCHECK(!IsEmpty());
	current_tile_ = PrioritizedTile();
	switch (phase_) {
	case EVENTUALLY_RECT:
	++eventually_iterator_;
	if (!eventually_iterator_.done())
	current_tile_ = *eventually_iterator_;
	break;
	case SOON_BORDER_RECT:
	++soon_iterator_;
	if (!soon_iterator_.done())
	current_tile_ = *soon_iterator_;
	break;
	case SKEWPORT_RECT:
	++skewport_iterator_;
	if (!skewport_iterator_.done())
	current_tile_ = *skewport_iterator_;
	break;
	case PENDING_VISIBLE_RECT:
	case PENDING_VISIBLE_RECT_REQUIRED_FOR_ACTIVATION:
	++pending_visible_iterator_;
	if (!pending_visible_iterator_.done())
	current_tile_ = *pending_visible_iterator_;
	break;
	case VISIBLE_RECT_OCCLUDED:
	case VISIBLE_RECT_UNOCCLUDED:
	case VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_OCCLUDED:
	case VISIBLE_RECT_REQUIRED_FOR_ACTIVATION_UNOCCLUDED:
	++visible_iterator_;
	if (!visible_iterator_.done())
	current_tile_ = *visible_iterator_;
	break;
	}
	if (!current_tile_.tile())
	AdvancePhase();
	}

	// EvictionRectIterator
	TilingSetEvictionQueue::EvictionRectIterator::EvictionRectIterator()
	: tilings_(nullptr), tree_(ACTIVE_TREE), tiling_index_(0) {
	}

	TilingSetEvictionQueue::EvictionRectIterator::EvictionRectIterator(
	std::vector<PictureLayerTiling> tilings,
	WhichTree tree,
	PictureLayerTiling::PriorityRectType priority_rect_type)
	: tilings_(tilings),
	tree_(tree),
	priority_rect_type_(priority_rect_type),
	tiling_index_(0) {
	}

	template <typename TilingIteratorType>
	bool TilingSetEvictionQueue::EvictionRectIterator::AdvanceToNextTile(
	TilingIteratorType* iterator) {
	bool found_tile = false;
	while (!found_tile) {
	++(*iterator);
	if (!(*iterator)) {
	prioritized_tile_ = PrioritizedTile();
	break;
	}
	found_tile = GetFirstTileAndCheckIfValid(iterator);
	}
	return found_tile;
	}

	template <typename TilingIteratorType>
	bool TilingSetEvictionQueue::EvictionRectIterator::GetFirstTileAndCheckIfValid(
	TilingIteratorType* iterator) {
	PictureLayerTiling* tiling = (*tilings_)[tiling_index_];
	Tile* tile = tiling->TileAt(iterator->index_x(), iterator->index_y());
	prioritized_tile_ = PrioritizedTile();
	// If there's nothing to evict, return false.
	if (!tile \|\| !tile->draw_info().has_resource())
	return false;
	// After the pending visible rect has been processed, we must return false
	// for pending visible rect tiles as tiling iterators do not ignore those
	// tiles.
	if (priority_rect_type_ > PictureLayerTiling::PENDING_VISIBLE_RECT) {
	gfx::Rect tile_rect = tiling->tiling_data()->TileBounds(
	tile->tiling_i_index(), tile->tiling_j_index());
	if (tiling->pending_visible_rect().Intersects(tile_rect))
	return false;
	}
	(*tilings_)[tiling_index_]->UpdateRequiredStatesOnTile(tile);
	prioritized_tile_ = (*tilings_)[tiling_index_]->MakePrioritizedTile(
	tile, priority_rect_type_);
	// In other cases, the tile we got is a viable candidate, return true.
	return true;
	}

	// EventuallyTilingIterator
	TilingSetEvictionQueue::EventuallyTilingIterator::EventuallyTilingIterator(
	std::vector<PictureLayerTiling> tilings,
	WhichTree tree)
	: EvictionRectIterator(tilings, tree, PictureLayerTiling::EVENTUALLY_RECT) {
	// Find the first tiling with a tile.
	while (tiling_index_ < tilings_->size()) {
	if (!(*tilings_)[tiling_index_]->has_eventually_rect_tiles()) {
	++tiling_index_;
	continue;
	}
	iterator_ = TilingData::ReverseSpiralDifferenceIterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->current_eventually_rect(),
	(*tilings_)[tiling_index_]->current_skewport_rect(),
	(*tilings_)[tiling_index_]->current_soon_border_rect());
	if (!iterator_) {
	++tiling_index_;
	continue;
	}
	break;
	}
	if (tiling_index_ >= tilings_->size())
	return;
	if (!GetFirstTileAndCheckIfValid(&iterator_))
	++(*this);
	}

	TilingSetEvictionQueue::EventuallyTilingIterator&
	TilingSetEvictionQueue::EventuallyTilingIterator::
	operator++() {
	bool found_tile = AdvanceToNextTile(&iterator_);
	while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
	++tiling_index_;
	if (!(*tilings_)[tiling_index_]->has_eventually_rect_tiles())
	continue;
	iterator_ = TilingData::ReverseSpiralDifferenceIterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->current_eventually_rect(),
	(*tilings_)[tiling_index_]->current_skewport_rect(),
	(*tilings_)[tiling_index_]->current_soon_border_rect());
	if (!iterator_)
	continue;
	found_tile = GetFirstTileAndCheckIfValid(&iterator_);
	if (!found_tile)
	found_tile = AdvanceToNextTile(&iterator_);
	}
	return *this;
	}

	// SoonBorderTilingIterator
	TilingSetEvictionQueue::SoonBorderTilingIterator::SoonBorderTilingIterator(
	std::vector<PictureLayerTiling> tilings,
	WhichTree tree)
	: EvictionRectIterator(tilings,
	tree,
	PictureLayerTiling::SOON_BORDER_RECT) {
	// Find the first tiling with a tile.
	while (tiling_index_ < tilings_->size()) {
	if (!(*tilings_)[tiling_index_]->has_soon_border_rect_tiles()) {
	++tiling_index_;
	continue;
	}
	iterator_ = TilingData::ReverseSpiralDifferenceIterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->current_soon_border_rect(),
	(*tilings_)[tiling_index_]->current_skewport_rect(),
	(*tilings_)[tiling_index_]->current_visible_rect());
	if (!iterator_) {
	++tiling_index_;
	continue;
	}
	break;
	}
	if (tiling_index_ >= tilings_->size())
	return;
	if (!GetFirstTileAndCheckIfValid(&iterator_))
	++(*this);
	}

	TilingSetEvictionQueue::SoonBorderTilingIterator&
	TilingSetEvictionQueue::SoonBorderTilingIterator::
	operator++() {
	bool found_tile = AdvanceToNextTile(&iterator_);
	while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
	++tiling_index_;
	if (!(*tilings_)[tiling_index_]->has_soon_border_rect_tiles())
	continue;
	iterator_ = TilingData::ReverseSpiralDifferenceIterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->current_soon_border_rect(),
	(*tilings_)[tiling_index_]->current_skewport_rect(),
	(*tilings_)[tiling_index_]->current_visible_rect());
	if (!iterator_)
	continue;
	found_tile = GetFirstTileAndCheckIfValid(&iterator_);
	if (!found_tile)
	found_tile = AdvanceToNextTile(&iterator_);
	}
	return *this;
	}

	// SkewportTilingIterator
	TilingSetEvictionQueue::SkewportTilingIterator::SkewportTilingIterator(
	std::vector<PictureLayerTiling> tilings,
	WhichTree tree)
	: EvictionRectIterator(tilings, tree, PictureLayerTiling::SKEWPORT_RECT) {
	// Find the first tiling with a tile.
	while (tiling_index_ < tilings_->size()) {
	if (!(*tilings_)[tiling_index_]->has_skewport_rect_tiles()) {
	++tiling_index_;
	continue;
	}
	iterator_ = TilingData::ReverseSpiralDifferenceIterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->current_skewport_rect(),
	(*tilings_)[tiling_index_]->current_visible_rect(),
	(*tilings_)[tiling_index_]->current_visible_rect());
	if (!iterator_) {
	++tiling_index_;
	continue;
	}
	break;
	}
	if (tiling_index_ >= tilings_->size())
	return;
	if (!GetFirstTileAndCheckIfValid(&iterator_))
	++(*this);
	}

	TilingSetEvictionQueue::SkewportTilingIterator&
	TilingSetEvictionQueue::SkewportTilingIterator::
	operator++() {
	bool found_tile = AdvanceToNextTile(&iterator_);
	while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
	++tiling_index_;
	if (!(*tilings_)[tiling_index_]->has_skewport_rect_tiles())
	continue;
	iterator_ = TilingData::ReverseSpiralDifferenceIterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->current_skewport_rect(),
	(*tilings_)[tiling_index_]->current_visible_rect(),
	(*tilings_)[tiling_index_]->current_visible_rect());
	if (!iterator_)
	continue;
	found_tile = GetFirstTileAndCheckIfValid(&iterator_);
	if (!found_tile)
	found_tile = AdvanceToNextTile(&iterator_);
	}
	return *this;
	}

	// PendingVisibleIterator
	TilingSetEvictionQueue::PendingVisibleTilingIterator::
	PendingVisibleTilingIterator(std::vector<PictureLayerTiling> tilings,
	WhichTree tree,
	bool return_required_for_activation_tiles)
	: EvictionRectIterator(tilings,
	tree,
	PictureLayerTiling::PENDING_VISIBLE_RECT),
	return_required_for_activation_tiles_(
	return_required_for_activation_tiles) {
	// Find the first tiling with a tile.
	while (tiling_index_ < tilings_->size()) {
	iterator_ = TilingData::DifferenceIterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->pending_visible_rect(),
	(*tilings_)[tiling_index_]->current_visible_rect());
	if (!iterator_) {
	++tiling_index_;
	continue;
	}
	break;
	}
	if (tiling_index_ >= tilings_->size())
	return;
	if (!GetFirstTileAndCheckIfValid(&iterator_)) {
	++(*this);
	return;
	}
	if (!TileMatchesRequiredFlags(prioritized_tile_)) {
	++(*this);
	return;
	}
	}

	TilingSetEvictionQueue::PendingVisibleTilingIterator&
	TilingSetEvictionQueue::PendingVisibleTilingIterator::
	operator++() {
	bool found_tile = AdvanceToNextTile(&iterator_);
	while (found_tile && !TileMatchesRequiredFlags(prioritized_tile_))
	found_tile = AdvanceToNextTile(&iterator_);

	while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
	++tiling_index_;
	iterator_ = TilingData::DifferenceIterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->pending_visible_rect(),
	(*tilings_)[tiling_index_]->current_visible_rect());
	if (!iterator_)
	continue;
	found_tile = GetFirstTileAndCheckIfValid(&iterator_);
	if (!found_tile)
	found_tile = AdvanceToNextTile(&iterator_);
	while (found_tile && !TileMatchesRequiredFlags(prioritized_tile_))
	found_tile = AdvanceToNextTile(&iterator_);
	}
	return *this;
	}

	bool TilingSetEvictionQueue::PendingVisibleTilingIterator::
	TileMatchesRequiredFlags(const PrioritizedTile& tile) const {
	bool activation_flag_matches = tile.tile()->required_for_activation() ==
	return_required_for_activation_tiles_;
	return activation_flag_matches;
	}

	// VisibleTilingIterator
	TilingSetEvictionQueue::VisibleTilingIterator::VisibleTilingIterator(
	std::vector<PictureLayerTiling> tilings,
	WhichTree tree,
	bool return_occluded_tiles,
	bool return_required_for_activation_tiles)
	: EvictionRectIterator(tilings, tree, PictureLayerTiling::VISIBLE_RECT),
	return_occluded_tiles_(return_occluded_tiles),
	return_required_for_activation_tiles_(
	return_required_for_activation_tiles) {
	// Find the first tiling with a tile.
	while (tiling_index_ < tilings_->size()) {
	if (!(*tilings_)[tiling_index_]->has_visible_rect_tiles()) {
	++tiling_index_;
	continue;
	}
	iterator_ = TilingData::Iterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->current_visible_rect(), false);
	if (!iterator_) {
	++tiling_index_;
	continue;
	}
	break;
	}
	if (tiling_index_ >= tilings_->size())
	return;
	if (!GetFirstTileAndCheckIfValid(&iterator_)) {
	++(*this);
	return;
	}
	if (!TileMatchesRequiredFlags(prioritized_tile_)) {
	++(*this);
	return;
	}
	}

	TilingSetEvictionQueue::VisibleTilingIterator&
	TilingSetEvictionQueue::VisibleTilingIterator::
	operator++() {
	bool found_tile = AdvanceToNextTile(&iterator_);
	while (found_tile && !TileMatchesRequiredFlags(prioritized_tile_))
	found_tile = AdvanceToNextTile(&iterator_);

	while (!found_tile && (tiling_index_ + 1) < tilings_->size()) {
	++tiling_index_;
	if (!(*tilings_)[tiling_index_]->has_visible_rect_tiles())
	continue;
	iterator_ = TilingData::Iterator(
	(*tilings_)[tiling_index_]->tiling_data(),
	(*tilings_)[tiling_index_]->current_visible_rect(), false);
	if (!iterator_)
	continue;
	found_tile = GetFirstTileAndCheckIfValid(&iterator_);
	if (!found_tile)
	found_tile = AdvanceToNextTile(&iterator_);
	while (found_tile && !TileMatchesRequiredFlags(prioritized_tile_))
	found_tile = AdvanceToNextTile(&iterator_);
	}
	return *this;
	}

	bool TilingSetEvictionQueue::VisibleTilingIterator::TileMatchesRequiredFlags(
	const PrioritizedTile& tile) const {
	bool activation_flag_matches = tile.tile()->required_for_activation() ==
	return_required_for_activation_tiles_;
	bool occluded_flag_matches = tile.is_occluded() == return_occluded_tiles_;
	return activation_flag_matches && occluded_flag_matches;
	}

	} // namespace cc