Revert 39942 - Switch NetworkChangeNotifier implementations to use ObserverList.

Fix up observer list so we can use FOR_EACH_OBSERVER when check_empty is set.
Clean up the ObserverList API a bit, replacing GetElementAt() with HasObserver() and Clear().
BUG=36590

Review URL: http://codereview.chromium.org/652205

TBR=willchan@chromium.org
Review URL: http://codereview.chromium.org/661029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@39945 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 104 insertions, 28 deletions

diff --git a/net/base/network_change_notifier_helper.cc b/net/base/network_change_notifier_helper.cc
new file mode 100644
index 0000000..052e3ef8
--- /dev/null
+++ b/net/base/network_change_notifier_helper.cc
@@ -0,0 +1,45 @@
+// Copyright (c) 2009 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 "net/base/network_change_notifier_helper.h"
+#include <algorithm>
+#include "base/logging.h"
+
+namespace net {
+
+namespace internal {
+
+NetworkChangeNotifierHelper::NetworkChangeNotifierHelper()
+    : is_notifying_observers_(false) {}
+
+NetworkChangeNotifierHelper::~NetworkChangeNotifierHelper() {
+  // TODO(willchan): Re-enable this DCHECK after fixing http://crbug.com/34391
+  // since we're leaking URLRequestContextGetters that cause this DCHECK to
+  // fire.
+  // DCHECK(observers_.empty());
+}
+
+void NetworkChangeNotifierHelper::AddObserver(Observer* observer) {
+  DCHECK(!is_notifying_observers_);
+  observers_.push_back(observer);
+}
+
+void NetworkChangeNotifierHelper::RemoveObserver(Observer* observer) {
+  DCHECK(!is_notifying_observers_);
+  observers_.erase(std::remove(observers_.begin(), observers_.end(), observer));
+}
+
+void NetworkChangeNotifierHelper::OnIPAddressChanged() {
+  DCHECK(!is_notifying_observers_);
+  is_notifying_observers_ = true;
+  for (std::vector<Observer*>::iterator it = observers_.begin();
+       it != observers_.end(); ++it) {
+    (*it)->OnIPAddressChanged();
+  }
+  is_notifying_observers_ = false;
+}
+
+}  // namespace internal
+
+}  // namespace net
diff --git a/net/base/network_change_notifier_helper.h b/net/base/network_change_notifier_helper.h
new file mode 100644
index 0000000..f860c45
--- /dev/null
+++ b/net/base/network_change_notifier_helper.h
@@ -0,0 +1,44 @@
+// Copyright (c) 2009 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.
+
+// NetworkChangeNotifierHelper is a helper class that assists in implementing
+// base functionality for a NetworkChangeNotifier implementation.  In
+// particular, it manages adding/removing observers and sending them
+// notifications of event changes.
+
+#ifndef NET_BASE_NETWORK_CHANGE_NOTIFIER_HELPER_H_
+#define NET_BASE_NETWORK_CHANGE_NOTIFIER_HELPER_H_
+
+#include <vector>
+#include "base/basictypes.h"
+#include "net/base/network_change_notifier.h"
+
+namespace net {
+
+namespace internal {
+
+class NetworkChangeNotifierHelper {
+ public:
+  typedef NetworkChangeNotifier::Observer Observer;
+
+  NetworkChangeNotifierHelper();
+  ~NetworkChangeNotifierHelper();
+
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  void OnIPAddressChanged();
+
+ private:
+  bool is_notifying_observers_;
+  std::vector<Observer*> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(NetworkChangeNotifierHelper);
+};
+
+}  // namespace internal
+
+}  // namespace net
+
+#endif  // NET_BASE_NETWORK_CHANGE_NOTIFIER_HELPER_H_
diff --git a/net/base/network_change_notifier_linux.cc b/net/base/network_change_notifier_linux.cc
index e6f5453..2a85c15 100644
--- a/net/base/network_change_notifier_linux.cc
+++ b/net/base/network_change_notifier_linux.cc
@@ -57,7 +57,7 @@ void NetworkChangeNotifierLinux::ListenForNotifications() {
   int rv = ReadNotificationMessage(buf, arraysize(buf));
   while (rv > 0 ) {
     if (HandleNetlinkMessage(buf, rv))
-      FOR_EACH_OBSERVER(Observer, observers_, OnIPAddressChanged());
+      helper_.OnIPAddressChanged();
     rv = ReadNotificationMessage(buf, arraysize(buf));
   }
 
diff --git a/net/base/network_change_notifier_linux.h b/net/base/network_change_notifier_linux.h
index 91d73e8..323ea55 100644
--- a/net/base/network_change_notifier_linux.h
+++ b/net/base/network_change_notifier_linux.h
@@ -7,8 +7,7 @@
 
 #include "base/basictypes.h"
 #include "base/message_loop.h"
-#include "base/observer_list.h"
-#include "net/base/network_change_notifier.h"
+#include "net/base/network_change_notifier_helper.h"
 
 namespace net {
 
@@ -20,11 +19,11 @@ class NetworkChangeNotifierLinux
   // NetworkChangeNotifier methods:
 
   virtual void AddObserver(Observer* observer) {
-    observers_.AddObserver(observer);
+    helper_.AddObserver(observer);
   }
 
   virtual void RemoveObserver(Observer* observer) {
-    observers_.RemoveObserver(observer);
+    helper_.RemoveObserver(observer);
   }
 
   // MessageLoopForIO::Watcher methods:
@@ -47,7 +46,7 @@ class NetworkChangeNotifierLinux
   // Handles the netlink message and notifies the observers.
   void HandleNotifications(const char* buf, size_t len);
 
-  ObserverList<Observer, true> observers_;
+  internal::NetworkChangeNotifierHelper helper_;
 
   int netlink_fd_;  // This is the netlink socket descriptor.
   MessageLoopForIO* const loop_;
diff --git a/net/base/network_change_notifier_mac.h b/net/base/network_change_notifier_mac.h
index 44d4806..5e777f4 100644
--- a/net/base/network_change_notifier_mac.h
+++ b/net/base/network_change_notifier_mac.h
@@ -6,11 +6,11 @@
 #define NET_BASE_NETWORK_CHANGE_NOTIFIER_MAC_H_
 
 #include "base/basictypes.h"
-#include "base/observer_list.h"
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 #include "base/task.h"
 #include "net/base/network_change_notifier.h"
+#include "net/base/network_change_notifier_helper.h"
 
 class MessageLoop;
 namespace base {
@@ -23,18 +23,16 @@ class NetworkChangeNotifierMac : public NetworkChangeNotifier {
  public:
   NetworkChangeNotifierMac();
 
-  void OnIPAddressChanged() {
-    FOR_EACH_OBSERVER(Observer, observers_, OnIPAddressChanged());
-  }
+  void OnIPAddressChanged() { helper_.OnIPAddressChanged(); }
 
   // NetworkChangeNotifier methods:
 
   virtual void AddObserver(Observer* observer) {
-    observers_.AddObserver(observer);
+    helper_.AddObserver(observer);
   }
 
   virtual void RemoveObserver(Observer* observer) {
-    observers_.RemoveObserver(observer);
+    helper_.RemoveObserver(observer);
   }
 
  private:
@@ -51,9 +49,7 @@ class NetworkChangeNotifierMac : public NetworkChangeNotifier {
   // Receives the OS X network change notifications on this thread.
   scoped_ptr<base::Thread> notifier_thread_;
 
-  // TODO(willchan): Fix the URLRequestContextGetter leaks and flip the false to
-  // true so we assert that all observers have been removed.
-  ObserverList<Observer, false> observers_;
+  internal::NetworkChangeNotifierHelper helper_;
 
   // Used to initialize the notifier thread.
   ScopedRunnableMethodFactory<NetworkChangeNotifierMac> method_factory_;
diff --git a/net/base/network_change_notifier_win.cc b/net/base/network_change_notifier_win.cc
index d139eb0f..e52bd46 100644
--- a/net/base/network_change_notifier_win.cc
+++ b/net/base/network_change_notifier_win.cc
@@ -3,11 +3,9 @@
 // found in the LICENSE file.
 
 #include "net/base/network_change_notifier_win.h"
-
 #include <iphlpapi.h>
 #include <windows.h>
 #include <winsock2.h>
-
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
diff --git a/net/base/network_change_notifier_win.h b/net/base/network_change_notifier_win.h
index 0f1f8d4..b11ec0d 100644
--- a/net/base/network_change_notifier_win.h
+++ b/net/base/network_change_notifier_win.h
@@ -7,8 +7,7 @@
 
 #include "base/basictypes.h"
 #include "base/object_watcher.h"
-#include "base/observer_list.h"
-#include "net/base/network_change_notifier.h"
+#include "net/base/network_change_notifier_helper.h"
 
 namespace net {
 
@@ -17,19 +16,16 @@ class NetworkChangeNotifierWin : public NetworkChangeNotifier {
   NetworkChangeNotifierWin();
 
   // Called by NetworkChangeNotifierWin::Impl.
-  void OnIPAddressChanged() {
-    FOR_EACH_OBSERVER(Observer, observers_, OnIPAddressChanged());
-  }
-
+  void OnIPAddressChanged() { helper_.OnIPAddressChanged(); }
 
   // NetworkChangeNotifier methods:
 
   virtual void AddObserver(Observer* observer) {
-    observers_.AddObserver(observer);
+    helper_.AddObserver(observer);
   }
 
   virtual void RemoveObserver(Observer* observer) {
-    observers_.RemoveObserver(observer);
+    helper_.RemoveObserver(observer);
   }
 
  private:
@@ -37,9 +33,7 @@ class NetworkChangeNotifierWin : public NetworkChangeNotifier {
 
   virtual ~NetworkChangeNotifierWin();
 
-  // TODO(willchan): Fix the URLRequestContextGetter leaks and flip the false to
-  // true so we assert that all observers have been removed.
-  ObserverList<Observer, false> observers_;
+  internal::NetworkChangeNotifierHelper helper_;
   scoped_ptr<Impl> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkChangeNotifierWin);