Revert of cc: Remove tile sharing from tilings.

cc/resources/raster_tile_priority_queue_required.cc

Index: cc/resources/raster_tile_priority_queue_required.cc
diff --git a/cc/resources/raster_tile_priority_queue_required.cc b/cc/resources/raster_tile_priority_queue_required.cc
index a6605fd3c53d71cce07ec2aec63a79157a5a4efb..3bf00ed33789aff3231aee88fe46898a24b498f9 100644
--- a/cc/resources/raster_tile_priority_queue_required.cc
+++ b/cc/resources/raster_tile_priority_queue_required.cc
@@ -18,45 +18,21 @@
     const std::vector<PictureLayerImpl::Pair>& paired_layers,
     Type type) {
   DCHECK_NE(static_cast<int>(type), static_cast<int>(Type::ALL));
-  if (type == Type::REQUIRED_FOR_DRAW)
-    BuildRequiredForDraw(paired_layers);
-  else
-    BuildRequiredForActivation(paired_layers);
-}
+  for (const auto& pair : paired_layers) {
+    PictureLayerTilingSet* tiling_set = nullptr;
+    if (type == Type::REQUIRED_FOR_DRAW && pair.active)
+      tiling_set = pair.active->picture_layer_tiling_set();
+    else if (type == Type::REQUIRED_FOR_ACTIVATION && pair.pending)
+      tiling_set = pair.pending->picture_layer_tiling_set();
 
-void RasterTilePriorityQueueRequired::BuildRequiredForDraw(
-    const std::vector<PictureLayerImpl::Pair>& paired_layers) {
-  for (const auto& pair : paired_layers) {
-    if (!pair.active)
+    if (!tiling_set)
       continue;
+
     scoped_ptr<TilingSetRasterQueueRequired> tiling_set_queue(
-        new TilingSetRasterQueueRequired(
-            pair.active->picture_layer_tiling_set(), Type::REQUIRED_FOR_DRAW));
+        new TilingSetRasterQueueRequired(tiling_set, type));
     if (tiling_set_queue->IsEmpty())
       continue;
     tiling_set_queues_.push_back(tiling_set_queue.Pass());
-  }
-}
-
-void RasterTilePriorityQueueRequired::BuildRequiredForActivation(
-    const std::vector<PictureLayerImpl::Pair>& paired_layers) {
-  for (const auto& pair : paired_layers) {
-    if (pair.active) {
-      scoped_ptr<TilingSetRasterQueueRequired> tiling_set_queue(
-          new TilingSetRasterQueueRequired(
-              pair.active->picture_layer_tiling_set(),
-              Type::REQUIRED_FOR_ACTIVATION));
-      if (!tiling_set_queue->IsEmpty())
-        tiling_set_queues_.push_back(tiling_set_queue.Pass());
-    }
-    if (pair.pending) {
-      scoped_ptr<TilingSetRasterQueueRequired> tiling_set_queue(
-          new TilingSetRasterQueueRequired(
-              pair.pending->picture_layer_tiling_set(),
-              Type::REQUIRED_FOR_ACTIVATION));
-      if (!tiling_set_queue->IsEmpty())
-        tiling_set_queues_.push_back(tiling_set_queue.Pass());
-    }
   }
 }