cc: Refactor how picture layers are exposed to the tile manager.

cc/resources/tile_manager.cc

Index: cc/resources/tile_manager.cc
diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index 4a4cfeaf27e340f9680c2260e4bdc4b92bb0aeb3..c96b5e27ffc643c55b808f524eb9054fff9c677a 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -420,13 +420,6 @@ TileManager::~TileManager() {
 
   DCHECK_EQ(0u, bytes_releasable_);
   DCHECK_EQ(0u, resources_releasable_);
-
-  for (std::vector<PictureLayerImpl*>::iterator it = layers_.begin();
-       it != layers_.end();
-       ++it) {
-    (*it)->DidUnregisterLayer();
-  }
-  layers_.clear();
 }
 
 void TileManager::Release(Tile* tile) {
@@ -676,19 +669,6 @@ void TileManager::GetTilesWithAssignedBins(PrioritizedTileSet* tiles) {
   }
 }
 
-void TileManager::CleanUpLayers() {
-  for (size_t i = 0; i < layers_.size(); ++i) {
-    if (layers_[i]->IsDrawnRenderSurfaceLayerListMember())
-      continue;
-
-    layers_[i]->DidUnregisterLayer();
-    std::swap(layers_[i], layers_.back());
-    layers_.pop_back();
-    --i;
-    prioritized_tiles_dirty_ = true;
-  }
-}
-
 void TileManager::ManageTiles(const GlobalStateThatImpactsTilePriority& state) {
   TRACE_EVENT0("cc", "TileManager::ManageTiles");
 
@@ -698,8 +678,6 @@ void TileManager::ManageTiles(const GlobalStateThatImpactsTilePriority& state) {
     prioritized_tiles_dirty_ = true;
   }
 
-  CleanUpLayers();
-
   // We need to call CheckForCompletedTasks() once in-between each call
   // to ScheduleTasks() to prevent canceled tasks from being scheduled.
   if (!did_check_for_completed_tasks_since_last_schedule_tasks_) {
@@ -1219,38 +1197,28 @@ scoped_refptr<Tile> TileManager::CreateTile(PicturePileImpl* picture_pile,
   return tile;
 }
 
-void TileManager::RegisterPictureLayerImpl(PictureLayerImpl* layer) {
-  DCHECK(std::find(layers_.begin(), layers_.end(), layer) == layers_.end());
-  layers_.push_back(layer);
-}
-
-void TileManager::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
-  std::vector<PictureLayerImpl*>::iterator it =
-      std::find(layers_.begin(), layers_.end(), layer);
-  DCHECK(it != layers_.end());
-  layers_.erase(it);
-}
-
 void TileManager::GetPairedPictureLayers(
     std::vector<PairedPictureLayer>* paired_layers) const {
+  const std::vector<PictureLayerImpl*>& layers = client_->GetPictureLayers();
+
   paired_layers->clear();
   // Reserve a maximum possible paired layers.
-  paired_layers->reserve(layers_.size());
+  paired_layers->reserve(layers.size());
 
-  for (std::vector<PictureLayerImpl*>::const_iterator it = layers_.begin();
-       it != layers_.end();
+  for (std::vector<PictureLayerImpl*>::const_iterator it = layers.begin();
+       it != layers.end();
        ++it) {
     PictureLayerImpl* layer = *it;
 
-    // This is a recycle tree layer, we can safely skip since the tiles on this
-    // layer have to be accessible via the active tree.
-    if (!layer->IsOnActiveOrPendingTree())
+    // TODO(vmpstr): Iterators and should handle this instead. crbug.com/381704
+    if (!layer->HasValidTilePriorities())
       continue;
 
     PictureLayerImpl* twin_layer = layer->GetTwinLayer();
 
-    // If the twin layer is recycled, it is not a valid twin.
-    if (twin_layer && !twin_layer->IsOnActiveOrPendingTree())
+    // Ignore the twin layer when tile priorities are invalid.
+    // TODO(vmpstr): Iterators should handle this instead. crbug.com/381704
+    if (twin_layer && !twin_layer->HasValidTilePriorities())
       twin_layer = NULL;
 
     PairedPictureLayer paired_layer;
@@ -1450,6 +1418,8 @@ bool TileManager::RasterTileIterator::RasterOrderComparator::operator()(
 
   // If the bin is the same but the resolution is not, then the order will be
   // determined by whether we prioritize low res or not.
+  // TODO(vmpstr): Remove this when TilePriority is no longer a member of Tile
+  // class but instead produced by the iterators.
   if (b_priority.priority_bin == a_priority.priority_bin &&
       b_priority.resolution != a_priority.resolution) {
     // Non ideal resolution should be sorted lower than other resolutions.
@@ -1639,8 +1609,10 @@ void TileManager::SetRasterizerForTesting(Rasterizer* rasterizer) {
 }
 
 bool TileManager::IsReadyToActivate() const {
-  for (std::vector<PictureLayerImpl*>::const_iterator it = layers_.begin();
-       it != layers_.end();
+  const std::vector<PictureLayerImpl*>& layers = client_->GetPictureLayers();
+
+  for (std::vector<PictureLayerImpl*>::const_iterator it = layers.begin();
+       it != layers.end();
        ++it) {
     if (!(*it)->AllTilesRequiredForActivationAreReadyToDraw())
       return false;