Upstream various ios/web utilities and helpers

ios/web/weak_nsobject_counter_unittest.mm

+// 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.
+
+#import "ios/web/weak_nsobject_counter.h"
+
+#import <Foundation/Foundation.h>
+
+#import "base/ios/weak_nsobject.h"
+#import "base/mac/scoped_nsobject.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+// Tests that a WeakNSObjectCounter correctly maintains a weak reference and
+// calculates the size correctly when many objects are added.
+TEST(WeakNSObjectCounter, ManyObjects) {
+  web::WeakNSObjectCounter object_counter;
+  base::scoped_nsobject<NSObject> p1([[NSObject alloc] init]);
+  base::scoped_nsobject<NSObject> p2([[NSObject alloc] init]);
+  base::scoped_nsobject<NSObject> p3([[NSObject alloc] init]);
+  object_counter.Insert(p1);
+  EXPECT_EQ(1U, object_counter.Size());
+  object_counter.Insert(p2);
+  EXPECT_EQ(2U, object_counter.Size());
+  object_counter.Insert(p3);
+  EXPECT_EQ(3U, object_counter.Size());
+  // Make sure p3 is correctly removed from the object counter.
+  p3.reset();
+  EXPECT_FALSE(p3);
+  EXPECT_EQ(2U, object_counter.Size());
+  // Make sure p2 is correctly removed from the object counter.
+  p2.reset();
+  EXPECT_EQ(1U, object_counter.Size());
+  // Make sure p1 is correctly removed from the object counter.
+  p1.reset();
+  EXPECT_FALSE(p1);
+  EXPECT_EQ(0U, object_counter.Size());
+}
+
+// Tests that WeakNSObjectCounter correctly works when the object outlives the
+// WeakNSObjectCounter that is observing it.
+TEST(WeakNSObjectCounter, ObjectOutlivesWeakNSObjectCounter) {
+  base::scoped_nsobject<NSObject> p1([[NSObject alloc] init]);
+  {
+    web::WeakNSObjectCounter object_counter;
+    object_counter.Insert(p1);
+    EXPECT_EQ(1U, object_counter.Size());
+  }
+  p1.reset();
+  EXPECT_FALSE(p1);
+}
+
+// Tests that WeakNSObjectCounter does not add the same object twice.
+TEST(WeakNSObjectCounter, SameObject) {
+  base::scoped_nsobject<NSObject> p1([[NSObject alloc] init]);
+  base::WeakNSObject<NSObject> p2(p1);
+  // Make sure they are the same object.
+  ASSERT_EQ(p1, p2);
+  web::WeakNSObjectCounter object_counter;
+  object_counter.Insert(p1);
+  EXPECT_EQ(1U, object_counter.Size());
+  object_counter.Insert(p2);
+  EXPECT_EQ(1U, object_counter.Size());
+}
+
+// Tests that WeakNSObjectCounter correctly maintains a reference to the object
+// and reduces its size only when the last reference to the object goes away.
+TEST(WeakNSObjectCounter, LastReference) {
+  web::WeakNSObjectCounter object_counter;
+  base::scoped_nsobject<NSObject> p1([[NSObject alloc] init]);
+  object_counter.Insert(p1);
+  EXPECT_EQ(1U, object_counter.Size());
+  base::scoped_nsobject<NSObject> p2(p1);
+  base::scoped_nsobject<NSObject> p3(p1);
+  p1.reset();
+  EXPECT_EQ(1U, object_counter.Size());
+  p2.reset();
+  EXPECT_EQ(1U, object_counter.Size());
+  // Last reference goes away.
+  p3.reset();
+  EXPECT_FALSE(object_counter.Size());
+}
+
+}  // namespace