Revert of cc: Remove tile sharing from tilings.

cc/test/fake_picture_layer_impl.cc

Index: cc/test/fake_picture_layer_impl.cc
diff --git a/cc/test/fake_picture_layer_impl.cc b/cc/test/fake_picture_layer_impl.cc
index dba0c6e300a1d636231f8137a89adc5f5d6bdaec..75f7fdafa4f1a927ae87d7437a1e82be297f235c 100644
--- a/cc/test/fake_picture_layer_impl.cc
+++ b/cc/test/fake_picture_layer_impl.cc
@@ -148,6 +148,9 @@
 }
 
 void FakePictureLayerImpl::SetAllTilesVisible() {
+  WhichTree tree =
+      layer_tree_impl()->IsActiveTree() ? ACTIVE_TREE : PENDING_TREE;
+
   for (size_t tiling_idx = 0; tiling_idx < tilings_->num_tilings();
        ++tiling_idx) {
     PictureLayerTiling* tiling = tilings_->tiling_at(tiling_idx);
@@ -158,7 +161,7 @@
       priority.resolution = HIGH_RESOLUTION;
       priority.priority_bin = TilePriority::NOW;
       priority.distance_to_visible = 0.f;
-      tile->set_priority(priority);
+      tile->SetPriority(tree, priority);
     }
   }
 }
@@ -170,7 +173,8 @@
     std::vector<Tile*> tiles = tiling->AllTilesForTesting();
     for (size_t tile_idx = 0; tile_idx < tiles.size(); ++tile_idx) {
       Tile* tile = tiles[tile_idx];
-      tile->set_priority(TilePriority());
+      tile->SetPriority(ACTIVE_TREE, TilePriority());
+      tile->SetPriority(PENDING_TREE, TilePriority());
     }
   }
 }
@@ -256,14 +260,16 @@
   if (!layer_tree_impl()->IsPendingTree())
     return 0;
 
-  return CountTilesRequired(&PictureLayerTiling::IsTileRequiredForActivation);
+  return CountTilesRequired(
+      &PictureLayerTiling::IsTileRequiredForActivationIfVisible);
 }
 
 size_t FakePictureLayerImpl::CountTilesRequiredForDraw() const {
   if (!layer_tree_impl()->IsActiveTree())
     return 0;
 
-  return CountTilesRequired(&PictureLayerTiling::IsTileRequiredForDraw);
+  return CountTilesRequired(
+      &PictureLayerTiling::IsTileRequiredForDrawIfVisible);
 }
 
 void FakePictureLayerImpl::ReleaseResources() {