Add a CallbackRegistry class to base/ to manage callbacks

base/callback_list_unittest.cc

Index: base/callback_list_unittest.cc
diff --git a/base/callback_list_unittest.cc b/base/callback_list_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a9c9caf0711d0b0429a4c51c45e10e37e31d2904
--- /dev/null
+++ b/base/callback_list_unittest.cc
@@ -0,0 +1,70 @@
+// Copyright (c) 2012 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 "base/callback_list.h"
+
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "base/threading/platform_thread.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace {
+
+class Listener {
+ public:
+  explicit Listener(int scaler) : total(0), scaler_(scaler) {}
+  virtual void OnEvent(int x) {
+    total += x * scaler_;
+  }
+  virtual ~Listener() {}
+  int total;
+
+ private:
+  int scaler_;
+};
+
+TEST(CallbackListTest, BasicTest) {
+  CallbackList<base::Callback<void(int)>> cb_list;
+  Listener a(1), b(-1), c(1), d(-1), e(-1);

[Avi (use Gerrit), 2013/08/21 19:56:18]

d and e aren't used

[Cait (Slow), 2013/08/22 15:30:25]

Done.

+
+  base::Closure remove_a = cb_list.RegisterCallback(
+      base::Bind(&Listener::OnEvent, base::Unretained(&a)));
+  base::Closure remove_b = cb_list.RegisterCallback(
+      base::Bind(&Listener::OnEvent, base::Unretained(&b)));
+
+  EXPECT_FALSE(remove_a.is_null());
+  EXPECT_FALSE(remove_b.is_null());
+
+  FOR_EACH_CALLBACK(base::Callback<void(int)>, cb_list, 10);
+
+  EXPECT_EQ(10, a.total);
+  EXPECT_EQ(-10, b.total);
+
+  remove_b.Run();
+
+  base::Closure remove_c = cb_list.RegisterCallback(
+      base::Bind(&Listener::OnEvent, base::Unretained(&c)));
+
+  FOR_EACH_CALLBACK(base::Callback<void(int)>, cb_list, 10);
+
+  EXPECT_EQ(20, a.total);
+  EXPECT_EQ(-10, b.total);
+  EXPECT_EQ(10, c.total);
+
+  remove_a.Run();
+  remove_b.Run();
+  remove_c.Run();
+
+  EXPECT_FALSE(cb_list.might_have_callbacks());
+

[Avi (use Gerrit), 2013/08/21 19:56:18]

drop blank line

[Cait (Slow), 2013/08/22 15:30:25]

Done.

+}
+
+
+}  // namespace
+}  // namespace base