cc: Add RandomAccessListContainer, which has more restricted API.

cc/base/list_container_unittest.cc

 // Copyright 2014 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/list_container.h"
 
 #include <algorithm>
 #include <vector>
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 68 matching lines @@
 }
 
 const int kMagicNumberToUseForSimpleDerivedElementOne = 42;
 const int kMagicNumberToUseForSimpleDerivedElementTwo = 314;
 const int kMagicNumberToUseForSimpleDerivedElementThree = 1618;
 
 class SimpleDerivedElement : public DerivedElement {
  public:
   ~SimpleDerivedElement() override {}
   void set_value(int val) { value = val; }
-  int get_value() { return value; }
+  int get_value() const { return value; }
 
  private:
   int value;
 };
 
 class SimpleDerivedElementConstructMagicNumberOne
     : public SimpleDerivedElement {
  public:
   SimpleDerivedElementConstructMagicNumberOne() {
     set_value(kMagicNumberToUseForSimpleDerivedElementOne);
@@ skipping 1094 matching lines @@
   // The capacity should shrink with the list.
   for (int i = 0; i < iterations; i++) {
     size_t capacity = list.GetCapacityInBytes();
     ASSERT_GE(capacity, list.size() * LargestDerivedElementSize());
     ASSERT_LE(capacity, std::max(list.size(), upper_bound_on_min_capacity) *
                             max_waste_factor * LargestDerivedElementSize());
     list.RemoveLast();
   }
 }
 
+TEST(RandomAccessListContainerTest, RandomAccess) {
+  RandomAccessListContainer<SimpleDerivedElement> list(
+      LargestDerivedElementSize(), 1);
+
+  list.AllocateAndConstruct<SimpleDerivedElementConstructMagicNumberOne>();
+  list.AllocateAndConstruct<SimpleDerivedElementConstructMagicNumberTwo>();
+  list.AllocateAndConstruct<SimpleDerivedElementConstructMagicNumberThree>();
+  list.AllocateAndConstruct<SimpleDerivedElementConstructMagicNumberOne>();
+  list.AllocateAndConstruct<SimpleDerivedElementConstructMagicNumberTwo>();
+  list.AllocateAndConstruct<SimpleDerivedElementConstructMagicNumberThree>();
+
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementOne, list[0]->get_value());
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementTwo, list[1]->get_value());
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementThree,
+            list[2]->get_value());
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementOne, list[3]->get_value());
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementTwo, list[4]->get_value());
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementThree,
+            list[5]->get_value());
+
+  list.RemoveLast();
+  list.RemoveLast();
+  list.RemoveLast();
+
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementOne, list[0]->get_value());
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementTwo, list[1]->get_value());
+  EXPECT_EQ(kMagicNumberToUseForSimpleDerivedElementThree,
+            list[2]->get_value());
+}
+
 }  // namespace
 }  // namespace cc