cc: Implement geometry-based tile eviction

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 111a0e718312d6db50ee2e318099a43ea32116e5..626b3a576857b0a15e92e13e539dc671fcc630fc 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -1563,6 +1563,7 @@ void PictureLayerImpl::LayerRasterTileIterator::AdvanceToNextStage() {
 PictureLayerImpl::LayerEvictionTileIterator::LayerEvictionTileIterator()
     : layer_(nullptr),
       tree_priority_(SAME_PRIORITY_FOR_BOTH_TREES),
+      layer_has_twin_layer_(false),
       current_category_(PictureLayerTiling::EVENTUALLY),
       current_tiling_range_type_(PictureLayerTilingSet::HIGHER_THAN_HIGH_RES),
       current_tiling_(0u) {
@@ -1573,6 +1574,7 @@ PictureLayerImpl::LayerEvictionTileIterator::LayerEvictionTileIterator(
     TreePriority tree_priority)
     : layer_(layer),
       tree_priority_(tree_priority),
+      layer_has_twin_layer_(!!layer->GetPendingOrActiveTwinLayer()),
       current_category_(PictureLayerTiling::EVENTUALLY),
       current_tiling_range_type_(PictureLayerTilingSet::HIGHER_THAN_HIGH_RES),
       current_tiling_(0u) {
@@ -1586,9 +1588,8 @@ PictureLayerImpl::LayerEvictionTileIterator::LayerEvictionTileIterator(
       break;
 
     current_iterator_ = PictureLayerTiling::TilingEvictionTileIterator(
-        layer_->tilings_->tiling_at(CurrentTilingIndex()),
-        tree_priority,
-        current_category_);
+        layer_->tilings_->tiling_at(CurrentTilingIndex()), tree_priority,
+        current_category_, layer_has_twin_layer_);
   } while (!current_iterator_);
 }
 
@@ -1615,9 +1616,8 @@ operator++() {
       break;
 
     current_iterator_ = PictureLayerTiling::TilingEvictionTileIterator(
-        layer_->tilings_->tiling_at(CurrentTilingIndex()),
-        tree_priority_,
-        current_category_);
+        layer_->tilings_->tiling_at(CurrentTilingIndex()), tree_priority_,
+        current_category_, layer_has_twin_layer_);
   }
   return *this;
 }