Switch ObserverList::size() to ObserverList::might_have_observers() Pt.1

This is in preparation for making ObserverList::size() protected (see bug for details).

BUG=278526
TEST=no change
TBR=darin@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23190045

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@219580 0039d316-1c4b-4281-b951-d872f2087c98

18 files changed, 34 insertions, 33 deletions

diff --git a/ash/launcher/launcher_button.cc b/ash/launcher/launcher_button.cc
index 26677ae..7529f6f 100644
--- a/ash/launcher/launcher_button.cc
+++ b/ash/launcher/launcher_button.cc
@@ -67,7 +67,7 @@ class LauncherButtonAnimation : public ui::AnimationDelegate {
 
   void RemoveObserver(Observer* observer) {
     observers_.RemoveObserver(observer);
-    if (observers_.size() == 0)
+    if (!observers_.might_have_observers())
       animation_.Stop();
   }
 
diff --git a/ash/system/chromeos/network/network_icon_animation.cc b/ash/system/chromeos/network/network_icon_animation.cc
index 1169c67..2a6428c 100644
--- a/ash/system/chromeos/network/network_icon_animation.cc
+++ b/ash/system/chromeos/network/network_icon_animation.cc
@@ -45,7 +45,7 @@ void NetworkIconAnimation::AddObserver(AnimationObserver* observer) {
 
 void NetworkIconAnimation::RemoveObserver(AnimationObserver* observer) {
   observers_.RemoveObserver(observer);
-  if (observers_.size() == 0)
+  if (!observers_.might_have_observers())
     animation_.Reset();  // Stops the animation and resets the current value.
 }
 
diff --git a/chrome/browser/chromeos/cros/network_library_impl_base.cc b/chrome/browser/chromeos/cros/network_library_impl_base.cc
index 6d38e02..9b169a5 100644
--- a/chrome/browser/chromeos/cros/network_library_impl_base.cc
+++ b/chrome/browser/chromeos/cros/network_library_impl_base.cc
@@ -127,7 +127,7 @@ void NetworkLibraryImplBase::RemoveNetworkObserver(
       network_observers_.find(service_path);
   if (map_iter != network_observers_.end()) {
     map_iter->second->RemoveObserver(observer);
-    if (!map_iter->second->size()) {
+    if (!map_iter->second->might_have_observers()) {
       MonitorNetworkStop(service_path);
       delete map_iter->second;
       network_observers_.erase(map_iter);
@@ -141,7 +141,7 @@ void NetworkLibraryImplBase::RemoveObserverForAllNetworks(
   NetworkObserverMap::iterator map_iter = network_observers_.begin();
   while (map_iter != network_observers_.end()) {
     map_iter->second->RemoveObserver(observer);
-    if (!map_iter->second->size()) {
+    if (!map_iter->second->might_have_observers()) {
       MonitorNetworkStop(map_iter->first);
       delete map_iter->second;
       network_observers_.erase(map_iter++);
diff --git a/chrome/browser/download/download_path_reservation_tracker_unittest.cc b/chrome/browser/download/download_path_reservation_tracker_unittest.cc
index 06183a5..5703da3 100644
--- a/chrome/browser/download/download_path_reservation_tracker_unittest.cc
+++ b/chrome/browser/download/download_path_reservation_tracker_unittest.cc
@@ -35,7 +35,7 @@ class FakeDownloadItem : public MockDownloadItem {
   }
   virtual ~FakeDownloadItem() {
     FOR_EACH_OBSERVER(Observer, observers_, OnDownloadDestroyed(this));
-    EXPECT_EQ(0u, observers_.size());
+    EXPECT_FALSE(observers_.might_have_observers());
   }
   virtual void AddObserver(Observer* observer) OVERRIDE {
     observers_.AddObserver(observer);
diff --git a/chrome/browser/net/pref_proxy_config_tracker_impl.cc b/chrome/browser/net/pref_proxy_config_tracker_impl.cc
index 5dd3e5d..fbf5e0c 100644
--- a/chrome/browser/net/pref_proxy_config_tracker_impl.cc
+++ b/chrome/browser/net/pref_proxy_config_tracker_impl.cc
@@ -79,7 +79,7 @@ void ChromeProxyConfigService::UpdateProxyConfig(
   pref_config_state_ = config_state;
   pref_config_ = config;
 
-  if (!observers_.size())
+  if (!observers_.might_have_observers())
     return;
 
   // Evaluate the proxy configuration. If GetLatestProxyConfig returns
diff --git a/chrome/browser/policy/policy_service_impl.cc b/chrome/browser/policy/policy_service_impl.cc
index 6af7605..2cfdcbb 100644
--- a/chrome/browser/policy/policy_service_impl.cc
+++ b/chrome/browser/policy/policy_service_impl.cc
@@ -56,7 +56,7 @@ void PolicyServiceImpl::RemoveObserver(PolicyDomain domain,
     return;
   }
   it->second->RemoveObserver(observer);
-  if (it->second->size() == 0) {
+  if (!it->second->might_have_observers()) {
     delete it->second;
     observers_.erase(it);
   }
diff --git a/chrome/browser/status_icons/status_icon.cc b/chrome/browser/status_icons/status_icon.cc
index 00270d2..52a36ab 100644
--- a/chrome/browser/status_icons/status_icon.cc
+++ b/chrome/browser/status_icons/status_icon.cc
@@ -22,7 +22,7 @@ void StatusIcon::RemoveObserver(StatusIconObserver* observer) {
 }
 
 bool StatusIcon::HasObservers() const {
-  return observers_.size() > 0;
+  return observers_.might_have_observers();
 }
 
 void StatusIcon::DispatchClickEvent() {
diff --git a/chrome/browser/ui/panels/display_settings_provider.cc b/chrome/browser/ui/panels/display_settings_provider.cc
index adf5ff2..42d76cc 100644
--- a/chrome/browser/ui/panels/display_settings_provider.cc
+++ b/chrome/browser/ui/panels/display_settings_provider.cc
@@ -43,9 +43,10 @@ void DisplaySettingsProvider::RemoveDesktopBarObserver(
 void DisplaySettingsProvider::AddFullScreenObserver(
     FullScreenObserver* observer) {
   is_full_screen_ = IsFullScreen();
+  bool already_started = full_screen_observers_.might_have_observers();
   full_screen_observers_.AddObserver(observer);
 
-  if (full_screen_observers_.size() == 1 && NeedsPeriodicFullScreenCheck()) {
+  if (!already_started && NeedsPeriodicFullScreenCheck()) {
     full_screen_mode_timer_.Start(FROM_HERE,
         base::TimeDelta::FromMilliseconds(kFullScreenModeCheckIntervalMs),
         base::Bind(&DisplaySettingsProvider::CheckFullScreenMode,
@@ -58,7 +59,7 @@ void DisplaySettingsProvider::RemoveFullScreenObserver(
     FullScreenObserver* observer) {
   full_screen_observers_.RemoveObserver(observer);
 
-  if (full_screen_observers_.size() == 0)
+  if (!full_screen_observers_.might_have_observers())
     full_screen_mode_timer_.Stop();
 }
 
diff --git a/chrome/browser/ui/panels/panel_mouse_watcher.cc b/chrome/browser/ui/panels/panel_mouse_watcher.cc
index b55ca76..1774658 100644
--- a/chrome/browser/ui/panels/panel_mouse_watcher.cc
+++ b/chrome/browser/ui/panels/panel_mouse_watcher.cc
@@ -14,15 +14,16 @@ PanelMouseWatcher::~PanelMouseWatcher() {
 }
 
 void PanelMouseWatcher::AddObserver(PanelMouseWatcherObserver* observer) {
+  bool already_started = observers_.might_have_observers();
   observers_.AddObserver(observer);
-  if (observers_.size() == 1)
+  if (!already_started)
     Start();
 }
 
 void PanelMouseWatcher::RemoveObserver(PanelMouseWatcherObserver* observer) {
   DCHECK(observers_.HasObserver(observer));
   observers_.RemoveObserver(observer);
-  if (observers_.size() == 0)
+  if (!observers_.might_have_observers())
     Stop();
 }
 
diff --git a/chromeos/dbus/shill_client_helper.cc b/chromeos/dbus/shill_client_helper.cc
index 61dcb4d..a0af3b8 100644
--- a/chromeos/dbus/shill_client_helper.cc
+++ b/chromeos/dbus/shill_client_helper.cc
@@ -180,9 +180,8 @@ ShillClientHelper::ShillClientHelper(dbus::Bus* bus,
 }
 
 ShillClientHelper::~ShillClientHelper() {
-  LOG_IF(ERROR, observer_list_.size() != 0u)
-      << "ShillClientHelper destroyed with active observers: "
-      << observer_list_.size();
+  LOG_IF(ERROR, observer_list_.might_have_observers())
+      << "ShillClientHelper destroyed with active observers";
 }
 
 void ShillClientHelper::AddPropertyChangedObserver(
@@ -203,7 +202,7 @@ void ShillClientHelper::RemovePropertyChangedObserver(
 
 void ShillClientHelper::MonitorPropertyChanged(
     const std::string& interface_name) {
-  if (observer_list_.size() > 0) {
+  if (observer_list_.might_have_observers()) {
     // Effectively monitor the PropertyChanged now.
     MonitorPropertyChangedInternal(interface_name);
   } else {
diff --git a/chromeos/dbus/shill_manager_client_stub.cc b/chromeos/dbus/shill_manager_client_stub.cc
index 640949a..b601eb2 100644
--- a/chromeos/dbus/shill_manager_client_stub.cc
+++ b/chromeos/dbus/shill_manager_client_stub.cc
@@ -523,7 +523,7 @@ void ShillManagerClientStub::CallNotifyObserversPropertyChanged(
     int delay_ms) {
   // Avoid unnecessary delayed task if we have no observers (e.g. during
   // initial setup).
-  if (observer_list_.size() == 0)
+  if (!observer_list_.might_have_observers())
     return;
   if (!CommandLine::ForCurrentProcess()->HasSwitch(
           chromeos::switches::kEnableStubInteractive)) {
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index d4f6e53..2a4ad9a 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -1813,7 +1813,7 @@ void ResourceDispatcherHostImpl::UnregisterResourceMessageDelegate(
   DelegateMap::iterator it = delegate_map_.find(id);
   DCHECK(it->second->HasObserver(delegate));
   it->second->RemoveObserver(delegate);
-  if (it->second->size() == 0) {
+  if (!it->second->might_have_observers()) {
     delete it->second;
     delegate_map_.erase(it);
   }
diff --git a/content/browser/media/webrtc_internals.cc b/content/browser/media/webrtc_internals.cc
index f8bcdc3..e94447a 100644
--- a/content/browser/media/webrtc_internals.cc
+++ b/content/browser/media/webrtc_internals.cc
@@ -65,7 +65,7 @@ void WebRTCInternals::OnAddPeerConnection(int render_process_id,
   dict->SetString("url", url);
   peer_connection_data_.Append(dict);
 
-  if (observers_.size() > 0)
+  if (observers_.might_have_observers())
     SendUpdate("addPeerConnection", dict);
 }
 
@@ -85,7 +85,7 @@ void WebRTCInternals::OnRemovePeerConnection(ProcessId pid, int lid) {
 
     peer_connection_data_.Remove(i, NULL);
 
-    if (observers_.size() > 0) {
+    if (observers_.might_have_observers()) {
       base::DictionaryValue id;
       id.SetInteger("pid", static_cast<int>(pid));
       id.SetInteger("lid", lid);
@@ -123,7 +123,7 @@ void WebRTCInternals::OnUpdatePeerConnection(
     log_entry->SetString("value", value);
     log->Append(log_entry);
 
-    if (observers_.size() > 0) {
+    if (observers_.might_have_observers()) {
       base::DictionaryValue update;
       update.SetInteger("pid", static_cast<int>(pid));
       update.SetInteger("lid", lid);
@@ -138,7 +138,7 @@ void WebRTCInternals::OnUpdatePeerConnection(
 
 void WebRTCInternals::OnAddStats(base::ProcessId pid, int lid,
                                  const base::ListValue& value) {
-  if (observers_.size() == 0)
+  if (!observers_.might_have_observers())
     return;
 
   base::DictionaryValue dict;
@@ -165,7 +165,7 @@ void WebRTCInternals::RemoveObserver(WebRTCInternalsUIObserver *observer) {
 }
 
 void WebRTCInternals::SendAllUpdates() {
-  if (observers_.size() > 0)
+  if (observers_.might_have_observers())
     SendUpdate("updateAllPeerConnections", &peer_connection_data_);
 }
 
@@ -184,7 +184,7 @@ void WebRTCInternals::StopRtpRecording() {
 }
 
 void WebRTCInternals::SendUpdate(const string& command, base::Value* value) {
-  DCHECK_GT(observers_.size(), (size_t)0);
+  DCHECK(observers_.might_have_observers());
 
   FOR_EACH_OBSERVER(WebRTCInternalsUIObserver,
                     observers_,
@@ -216,7 +216,7 @@ void WebRTCInternals::OnRendererExit(int render_process_id) {
     record->GetInteger("rid", &this_rid);
 
     if (this_rid == render_process_id) {
-      if (observers_.size() > 0) {
+      if (observers_.might_have_observers()) {
         int lid = 0, pid = 0;
         record->GetInteger("lid", &lid);
         record->GetInteger("pid", &pid);
diff --git a/content/browser/notification_service_impl.cc b/content/browser/notification_service_impl.cc
index 4913288..27de857 100644
--- a/content/browser/notification_service_impl.cc
+++ b/content/browser/notification_service_impl.cc
@@ -83,7 +83,7 @@ void NotificationServiceImpl::RemoveObserver(NotificationObserver* observer,
       observers_[type][source.map_key()];
   if (observer_list) {
     observer_list->RemoveObserver(observer);
-    if (!observer_list->size()) {
+    if (!observer_list->might_have_observers()) {
       observers_[type].erase(source.map_key());
       delete observer_list;
     }
diff --git a/media/base/user_input_monitor.cc b/media/base/user_input_monitor.cc
index 18b4c80..8a1f1da 100644
--- a/media/base/user_input_monitor.cc
+++ b/media/base/user_input_monitor.cc
@@ -33,7 +33,7 @@ void UserInputMonitor::AddMouseListener(MouseEventListener* listener) {
 void UserInputMonitor::RemoveMouseListener(MouseEventListener* listener) {
   base::AutoLock auto_lock(lock_);
   mouse_listeners_.RemoveObserver(listener);
-  if (mouse_listeners_.size() == 0) {
+  if (!mouse_listeners_.might_have_observers()) {
     StopMouseMonitoring();
     monitoring_mouse_ = false;
     DVLOG(2) << "Stopped mouse monitoring.";
@@ -51,7 +51,7 @@ void UserInputMonitor::AddKeyStrokeListener(KeyStrokeListener* listener) {
 void UserInputMonitor::RemoveKeyStrokeListener(KeyStrokeListener* listener) {
   base::AutoLock auto_lock(lock_);
   key_stroke_listeners_.RemoveObserver(listener);
-  if (key_stroke_listeners_.size() == 0) {
+  if (!key_stroke_listeners_.might_have_observers()) {
     StopKeyboardMonitoring();
     monitoring_keyboard_ = false;
     DVLOG(2) << "Stopped keyboard monitoring.";
diff --git a/net/dns/mdns_client_impl.cc b/net/dns/mdns_client_impl.cc
index 8f79edf..a90ac64 100644
--- a/net/dns/mdns_client_impl.cc
+++ b/net/dns/mdns_client_impl.cc
@@ -378,7 +378,7 @@ void MDnsClientImpl::Core::RemoveListener(MDnsListenerImpl* listener) {
   observer_list_iterator->second->RemoveObserver(listener);
 
   // Remove the observer list from the map if it is empty
-  if (observer_list_iterator->second->size() == 0) {
+  if (!observer_list_iterator->second->might_have_observers()) {
     // Schedule the actual removal for later in case the listener removal
     // happens while iterating over the observer list.
     base::MessageLoop::current()->PostTask(
@@ -389,7 +389,7 @@ void MDnsClientImpl::Core::RemoveListener(MDnsListenerImpl* listener) {
 
 void MDnsClientImpl::Core::CleanupObserverList(const ListenerKey& key) {
   ListenerMap::iterator found = listeners_.find(key);
-  if (found != listeners_.end() && found->second->size() == 0) {
+  if (found != listeners_.end() && !found->second->might_have_observers()) {
     delete found->second;
     listeners_.erase(found);
   }
diff --git a/sync/js/sync_js_controller.cc b/sync/js/sync_js_controller.cc
index 49f3cc7..4d3148f 100644
--- a/sync/js/sync_js_controller.cc
+++ b/sync/js/sync_js_controller.cc
@@ -73,7 +73,7 @@ void SyncJsController::UpdateBackendEventHandler() {
     // event handler we pass to it if we don't have any event
     // handlers.
     WeakHandle<JsEventHandler> backend_event_handler =
-        (js_event_handlers_.size() > 0) ?
+        js_event_handlers_.might_have_observers() ?
         MakeWeakHandle(AsWeakPtr()) : WeakHandle<SyncJsController>();
     js_backend_.Call(FROM_HERE, &JsBackend::SetJsEventHandler,
                      backend_event_handler);
diff --git a/ui/compositor/layer_animator_unittest.cc b/ui/compositor/layer_animator_unittest.cc
index 8b4d792..5cae43c 100644
--- a/ui/compositor/layer_animator_unittest.cc
+++ b/ui/compositor/layer_animator_unittest.cc
@@ -1764,13 +1764,13 @@ TEST(LayerAnimatorTest, ObserverReleasedBeforeAnimationSequenceEnds) {
   animator->StartAnimation(sequence);
 
   // |observer| should be attached to |sequence|.
-  EXPECT_EQ(static_cast<size_t>(1), sequence->observers_.size());
+  EXPECT_TRUE(sequence->observers_.might_have_observers());
 
   // Now, release |observer|
   observer.reset();
 
   // And |sequence| should no longer be attached to |observer|.
-  EXPECT_EQ(static_cast<size_t>(0), sequence->observers_.size());
+  EXPECT_FALSE(sequence->observers_.might_have_observers());
 }
 
 TEST(LayerAnimatorTest, ObserverAttachedAfterAnimationStarted) {