cc: Remove tiles from recycle tree that were deleted on active.

cc/layers/picture_layer_impl_unittest.cc

Index: cc/layers/picture_layer_impl_unittest.cc
diff --git a/cc/layers/picture_layer_impl_unittest.cc b/cc/layers/picture_layer_impl_unittest.cc
index 8ccd54f37c3e02411aafee13f56dfc524b080aa4..f4187e9ace0d235fadfed218b7335898eef60fea 100644
--- a/cc/layers/picture_layer_impl_unittest.cc
+++ b/cc/layers/picture_layer_impl_unittest.cc
@@ -53,7 +53,10 @@ class PictureLayerImplTest : public testing::Test {
         host_impl_(ImplSidePaintingSettings(),
                    &proxy_,
                    &shared_bitmap_manager_),
-        id_(7) {}
+        id_(7),
+        pending_layer_(NULL),
+        old_pending_layer_(NULL),
+        active_layer_(NULL) {}
 
   explicit PictureLayerImplTest(const LayerTreeSettings& settings)
       : proxy_(base::MessageLoopProxy::current()),
@@ -86,6 +89,8 @@ class PictureLayerImplTest : public testing::Test {
   void ActivateTree() {
     host_impl_.ActivateSyncTree();
     CHECK(!host_impl_.pending_tree());
+    CHECK(host_impl_.recycle_tree());
+    old_pending_layer_ = pending_layer_;
     pending_layer_ = NULL;
     active_layer_ = static_cast<FakePictureLayerImpl*>(
         host_impl_.active_tree()->LayerById(id_));
@@ -266,6 +271,7 @@ class PictureLayerImplTest : public testing::Test {
   FakeLayerTreeHostImpl host_impl_;
   int id_;
   FakePictureLayerImpl* pending_layer_;
+  FakePictureLayerImpl* old_pending_layer_;
   FakePictureLayerImpl* active_layer_;
 
  private:
@@ -4145,5 +4151,31 @@ TEST_F(OcclusionTrackingPictureLayerImplTest,
   VerifyEvictionConsidersOcclusion(active_layer_,
                                    total_expected_occluded_tile_count);
 }
+
+TEST_F(PictureLayerImplTest, RecycledTwinLayer) {
+  gfx::Size tile_size(102, 102);
+  gfx::Size layer_bounds(1000, 1000);
+
+  scoped_refptr<FakePicturePileImpl> pile =
+      FakePicturePileImpl::CreateFilledPile(tile_size, layer_bounds);
+  SetupPendingTree(pile);
+  EXPECT_FALSE(pending_layer_->GetRecycledTwinLayer());
+
+  ActivateTree();
+  EXPECT_TRUE(active_layer_->GetRecycledTwinLayer());
+  EXPECT_EQ(old_pending_layer_, active_layer_->GetRecycledTwinLayer());
+
+  SetupPendingTree(pile);
+  EXPECT_FALSE(pending_layer_->GetRecycledTwinLayer());
+  EXPECT_FALSE(active_layer_->GetRecycledTwinLayer());
+
+  ActivateTree();
+  EXPECT_TRUE(active_layer_->GetRecycledTwinLayer());
+  EXPECT_EQ(old_pending_layer_, active_layer_->GetRecycledTwinLayer());
+
+  host_impl_.ResetRecycleTreeForTesting();
+  EXPECT_FALSE(active_layer_->GetRecycledTwinLayer());
+}
+
 }  // namespace
 }  // namespace cc