cc: Implement RemoveLast for DisplayItemList.

cc/base/sidecar_list_container_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/base/sidecar_list_container.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 164 matching lines @@
     num_elements++;
   }
   EXPECT_EQ(kNumElementsForTest, num_elements);
 
   container.clear();
   EXPECT_TRUE(container.empty());
   EXPECT_EQ(0u, container.size());
   EXPECT_EQ(container.end(), container.begin());
 }
 
+TEST(SidecarListContainerTest, RemoveLast) {
+  // We need only ensure that the sidecar is also destroyed on RemoveLast.
+  // The rest is logic already present in ListContainer.
+  bool sidecar_destroyed = false;
+  TestContainer container;
+  TestElement* element = container.AllocateAndConstruct<TestElement>();
+  new (container.GetSidecar(element)) TestSidecar(&sidecar_destroyed);
+  ASSERT_FALSE(sidecar_destroyed);
+  container.RemoveLast();
+  ASSERT_TRUE(sidecar_destroyed);
+}
+
 }  // namespace
 }  // namespace cc