Add logging for slow device events, limit network UI update rate

This CL does the following:
* Cleans up some redundant code in the network UI.
* Disassociates Network UI updates from dbus calls and limits the
  frequency of UI updates by using a timer to trigger updates.
* Adds NET_LOG_IF_SLOW to device_event_log.h to log slow network events.

Note: I also did virtual/override cleanup while in there and ran clang format on the changed files.

Original CL (reverted):
https://codereview.chromium.org/811623002

BUG=441650

Review URL: https://codereview.chromium.org/800893003

Cr-Commit-Position: refs/heads/master@{#310659}

9 files changed, 209 insertions, 273 deletions

diff --git a/ash/system/chromeos/network/network_detailed_view.h b/ash/system/chromeos/network/network_detailed_view.h
index 772f239..0d17c7a 100644
--- a/ash/system/chromeos/network/network_detailed_view.h
+++ b/ash/system/chromeos/network/network_detailed_view.h
@@ -29,17 +29,10 @@ class NetworkDetailedView : public TrayDetailsView {
 
   virtual DetailedViewType GetViewType() const = 0;
 
-  // Called when network manager state has changed.
-  // (Generic update for NetworkTray <> AshSystemTrayDelegate interface).
-  virtual void ManagerChanged() = 0;
-
-  // Called when the contents of the network list have changed.
-  // (Called only from TrayNetworkStateObserver).
-  virtual void NetworkListChanged() = 0;
-
-  // Called when a network service property has changed.
+  // Called when the contents of the network list have changed or when any
+  // Manager properties (e.g. technology state) have changed.
   // (Called only from TrayNetworkStateObserver).
-  virtual void NetworkServiceChanged(const chromeos::NetworkState* network) = 0;
+  virtual void Update() = 0;
 
  protected:
   virtual ~NetworkDetailedView() {}
diff --git a/ash/system/chromeos/network/network_state_list_detailed_view.cc b/ash/system/chromeos/network/network_state_list_detailed_view.cc
index 3f334b5..63d801a 100644
--- a/ash/system/chromeos/network/network_state_list_detailed_view.cc
+++ b/ash/system/chromeos/network/network_state_list_detailed_view.cc
@@ -24,6 +24,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "chromeos/chromeos_switches.h"
+#include "chromeos/device_event_log.h"
 #include "chromeos/network/device_state.h"
 #include "chromeos/network/network_configuration_handler.h"
 #include "chromeos/network/network_state.h"
@@ -82,7 +83,6 @@ views::View* CreateInfoBubbleLine(const base::string16& text_label,
 
 }  // namespace
 
-
 //------------------------------------------------------------------------------
 
 // A bubble which displays network info.
@@ -102,9 +102,7 @@ class NetworkStateListDetailedView::InfoBubble
     AddChildView(content);
   }
 
-  virtual ~InfoBubble() {
-    detailed_view_->OnInfoBubbleDestroyed();
-  }
+  ~InfoBubble() override { detailed_view_->OnInfoBubbleDestroyed(); }
 
  private:
   // Not owned.
@@ -141,26 +139,13 @@ NetworkStateListDetailedView::~NetworkStateListDetailedView() {
     info_bubble_->GetWidget()->CloseNow();
 }
 
-void NetworkStateListDetailedView::ManagerChanged() {
+void NetworkStateListDetailedView::Update() {
   UpdateNetworkList();
   UpdateHeaderButtons();
   UpdateNetworkExtra();
   Layout();
 }
 
-void NetworkStateListDetailedView::NetworkListChanged() {
-  UpdateNetworkList();
-  UpdateHeaderButtons();
-  UpdateNetworkExtra();
-  Layout();
-}
-
-void NetworkStateListDetailedView::NetworkServiceChanged(
-    const NetworkState* network) {
-  UpdateNetworkList();
-  Layout();
-}
-
 // Overridden from NetworkDetailedView:
 
 void NetworkStateListDetailedView::Init() {
@@ -181,7 +166,7 @@ void NetworkStateListDetailedView::Init() {
   CreateHeaderButtons();
 
   network_list_view_.set_content_view(scroll_content());
-  NetworkListChanged();
+  Update();
 
   CallRequestScan();
 }
@@ -207,22 +192,19 @@ void NetworkStateListDetailedView::ButtonPressed(views::Button* sender,
   ash::SystemTrayDelegate* delegate =
       ash::Shell::GetInstance()->system_tray_delegate();
   if (sender == button_wifi_) {
-    bool enabled = handler->IsTechnologyEnabled(
-        NetworkTypePattern::WiFi());
-    handler->SetTechnologyEnabled(NetworkTypePattern::WiFi(),
-                                  !enabled,
+    bool enabled = handler->IsTechnologyEnabled(NetworkTypePattern::WiFi());
+    handler->SetTechnologyEnabled(NetworkTypePattern::WiFi(), !enabled,
                                   chromeos::network_handler::ErrorCallback());
   } else if (sender == turn_on_wifi_) {
-    handler->SetTechnologyEnabled(NetworkTypePattern::WiFi(),
-                                  true,
+    handler->SetTechnologyEnabled(NetworkTypePattern::WiFi(), true,
                                   chromeos::network_handler::ErrorCallback());
   } else if (sender == button_mobile_) {
     ToggleMobile();
   } else if (sender == settings_) {
     Shell::GetInstance()->metrics()->RecordUserMetricsAction(
-        list_type_ == LIST_TYPE_VPN ?
-        ash::UMA_STATUS_AREA_VPN_SETTINGS_CLICKED :
-        ash::UMA_STATUS_AREA_NETWORK_SETTINGS_CLICKED);
+        list_type_ == LIST_TYPE_VPN
+            ? ash::UMA_STATUS_AREA_VPN_SETTINGS_CLICKED
+            : ash::UMA_STATUS_AREA_NETWORK_SETTINGS_CLICKED);
     delegate->ShowNetworkSettings("");
   } else if (sender == proxy_settings_) {
     delegate->ChangeProxySettings();
@@ -257,20 +239,21 @@ void NetworkStateListDetailedView::OnViewClicked(views::View* sender) {
   if (!network_list_view_.IsViewInList(sender, &service_path))
     return;
 
-  const NetworkState* network = NetworkHandler::Get()->network_state_handler()->
-      GetNetworkState(service_path);
+  const NetworkState* network =
+      NetworkHandler::Get()->network_state_handler()->GetNetworkState(
+          service_path);
   if (!network || network->IsConnectedState() || network->IsConnectingState()) {
     Shell::GetInstance()->metrics()->RecordUserMetricsAction(
-        list_type_ == LIST_TYPE_VPN ?
-        ash::UMA_STATUS_AREA_SHOW_NETWORK_CONNECTION_DETAILS :
-        ash::UMA_STATUS_AREA_SHOW_VPN_CONNECTION_DETAILS);
+        list_type_ == LIST_TYPE_VPN
+            ? ash::UMA_STATUS_AREA_SHOW_NETWORK_CONNECTION_DETAILS
+            : ash::UMA_STATUS_AREA_SHOW_VPN_CONNECTION_DETAILS);
     Shell::GetInstance()->system_tray_delegate()->ShowNetworkSettings(
         service_path);
   } else {
     Shell::GetInstance()->metrics()->RecordUserMetricsAction(
-        list_type_ == LIST_TYPE_VPN ?
-        ash::UMA_STATUS_AREA_CONNECT_TO_VPN :
-        ash::UMA_STATUS_AREA_CONNECT_TO_CONFIGURED_NETWORK);
+        list_type_ == LIST_TYPE_VPN
+            ? ash::UMA_STATUS_AREA_CONNECT_TO_VPN
+            : ash::UMA_STATUS_AREA_CONNECT_TO_CONFIGURED_NETWORK);
     ui::NetworkConnect::Get()->ConnectToNetwork(service_path);
   }
 }
@@ -284,25 +267,21 @@ void NetworkStateListDetailedView::CreateHeaderEntry() {
 void NetworkStateListDetailedView::CreateHeaderButtons() {
   if (list_type_ != LIST_TYPE_VPN) {
     button_wifi_ = new TrayPopupHeaderButton(
-        this,
-        IDR_AURA_UBER_TRAY_WIFI_ENABLED,
-        IDR_AURA_UBER_TRAY_WIFI_DISABLED,
+        this, IDR_AURA_UBER_TRAY_WIFI_ENABLED, IDR_AURA_UBER_TRAY_WIFI_DISABLED,
         IDR_AURA_UBER_TRAY_WIFI_ENABLED_HOVER,
-        IDR_AURA_UBER_TRAY_WIFI_DISABLED_HOVER,
-        IDS_ASH_STATUS_TRAY_WIFI);
+        IDR_AURA_UBER_TRAY_WIFI_DISABLED_HOVER, IDS_ASH_STATUS_TRAY_WIFI);
     button_wifi_->SetTooltipText(
         l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_DISABLE_WIFI));
     button_wifi_->SetToggledTooltipText(
         l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_ENABLE_WIFI));
     footer()->AddButton(button_wifi_);
 
-    button_mobile_ = new TrayPopupHeaderButton(
-        this,
-        IDR_AURA_UBER_TRAY_CELLULAR_ENABLED,
-        IDR_AURA_UBER_TRAY_CELLULAR_DISABLED,
-        IDR_AURA_UBER_TRAY_CELLULAR_ENABLED_HOVER,
-        IDR_AURA_UBER_TRAY_CELLULAR_DISABLED_HOVER,
-        IDS_ASH_STATUS_TRAY_CELLULAR);
+    button_mobile_ =
+        new TrayPopupHeaderButton(this, IDR_AURA_UBER_TRAY_CELLULAR_ENABLED,
+                                  IDR_AURA_UBER_TRAY_CELLULAR_DISABLED,
+                                  IDR_AURA_UBER_TRAY_CELLULAR_ENABLED_HOVER,
+                                  IDR_AURA_UBER_TRAY_CELLULAR_DISABLED_HOVER,
+                                  IDS_ASH_STATUS_TRAY_CELLULAR);
     button_mobile_->SetTooltipText(
         l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_DISABLE_MOBILE));
     button_mobile_->SetToggledTooltipText(
@@ -311,12 +290,9 @@ void NetworkStateListDetailedView::CreateHeaderButtons() {
   }
 
   info_icon_ = new TrayPopupHeaderButton(
-      this,
-      IDR_AURA_UBER_TRAY_NETWORK_INFO,
-      IDR_AURA_UBER_TRAY_NETWORK_INFO,
-      IDR_AURA_UBER_TRAY_NETWORK_INFO_HOVER,
+      this, IDR_AURA_UBER_TRAY_NETWORK_INFO, IDR_AURA_UBER_TRAY_NETWORK_INFO,
       IDR_AURA_UBER_TRAY_NETWORK_INFO_HOVER,
-      IDS_ASH_STATUS_TRAY_NETWORK_INFO);
+      IDR_AURA_UBER_TRAY_NETWORK_INFO_HOVER, IDS_ASH_STATUS_TRAY_NETWORK_INFO);
   info_icon_->SetTooltipText(
       l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_NETWORK_INFO));
   footer()->AddButton(info_icon_);
@@ -330,10 +306,8 @@ void NetworkStateListDetailedView::CreateNetworkExtra() {
 
   views::View* bottom_row = new views::View();
   views::BoxLayout* layout = new views::BoxLayout(
-      views::BoxLayout::kHorizontal,
-      kTrayMenuBottomRowPadding,
-      kTrayMenuBottomRowPadding,
-      kTrayMenuBottomRowPaddingBetweenItems);
+      views::BoxLayout::kHorizontal, kTrayMenuBottomRowPadding,
+      kTrayMenuBottomRowPadding, kTrayMenuBottomRowPaddingBetweenItems);
   layout->SetDefaultFlex(1);
   bottom_row->SetLayoutManager(layout);
 
@@ -351,9 +325,8 @@ void NetworkStateListDetailedView::CreateNetworkExtra() {
     bottom_row->AddChildView(other_mobile_);
   } else {
     other_vpn_ = new TrayPopupLabelButton(
-        this,
-        ui::ResourceBundle::GetSharedInstance().GetLocalizedString(
-            IDS_ASH_STATUS_TRAY_OTHER_VPN));
+        this, ui::ResourceBundle::GetSharedInstance().GetLocalizedString(
+                  IDS_ASH_STATUS_TRAY_OTHER_VPN));
     bottom_row->AddChildView(other_vpn_);
   }
 
@@ -466,8 +439,8 @@ void NetworkStateListDetailedView::UpdateNetworkExtra() {
     }
     if (show_other_mobile) {
       other_mobile_->SetVisible(true);
-      other_mobile_->SetEnabled(
-          state == NetworkStateHandler::TECHNOLOGY_ENABLED);
+      other_mobile_->SetEnabled(state ==
+                                NetworkStateHandler::TECHNOLOGY_ENABLED);
     } else {
       other_mobile_->SetVisible(false);
     }
@@ -481,8 +454,8 @@ void NetworkStateListDetailedView::UpdateNetworkExtra() {
 
 void NetworkStateListDetailedView::CreateSettingsEntry() {
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
-  bool show_settings = ash::Shell::GetInstance()->
-      system_tray_delegate()->ShouldShowSettings();
+  bool show_settings =
+      ash::Shell::GetInstance()->system_tray_delegate()->ShouldShowSettings();
   if (login_ != user::LOGGED_IN_NONE) {
     // Allow user access settings only if user is logged in
     // and showing settings is allowed. There're situations (supervised user
@@ -492,7 +465,7 @@ void NetworkStateListDetailedView::CreateSettingsEntry() {
       settings_ = new TrayPopupLabelButton(
           this, rb.GetLocalizedString(IDS_ASH_STATUS_TRAY_NETWORK_SETTINGS));
     }
-  } else  {
+  } else {
     // Allow users to change proxy settings only when not logged in.
     proxy_settings_ = new TrayPopupLabelButton(
         this,
@@ -504,8 +477,7 @@ void NetworkStateListDetailedView::ToggleInfoBubble() {
   if (ResetInfoBubble())
     return;
 
-  info_bubble_ = new InfoBubble(
-      info_icon_, CreateNetworkInfoView(), this);
+  info_bubble_ = new InfoBubble(info_icon_, CreateNetworkInfoView(), this);
   views::BubbleDelegateView::CreateBubble(info_bubble_)->Show();
 }
 
@@ -547,27 +519,28 @@ views::View* NetworkStateListDetailedView::CreateNetworkInfoView() {
   }
 
   if (!ip_address.empty()) {
-    container->AddChildView(CreateInfoBubbleLine(bundle.GetLocalizedString(
-        IDS_ASH_STATUS_TRAY_IP), ip_address));
+    container->AddChildView(CreateInfoBubbleLine(
+        bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_IP), ip_address));
   }
   if (!ethernet_address.empty()) {
-    container->AddChildView(CreateInfoBubbleLine(bundle.GetLocalizedString(
-        IDS_ASH_STATUS_TRAY_ETHERNET), ethernet_address));
+    container->AddChildView(CreateInfoBubbleLine(
+        bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_ETHERNET),
+        ethernet_address));
   }
   if (!wifi_address.empty()) {
-    container->AddChildView(CreateInfoBubbleLine(bundle.GetLocalizedString(
-        IDS_ASH_STATUS_TRAY_WIFI), wifi_address));
+    container->AddChildView(CreateInfoBubbleLine(
+        bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_WIFI), wifi_address));
   }
   if (!vpn_address.empty()) {
-    container->AddChildView(CreateInfoBubbleLine(bundle.GetLocalizedString(
-        IDS_ASH_STATUS_TRAY_VPN), vpn_address));
+    container->AddChildView(CreateInfoBubbleLine(
+        bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_VPN), vpn_address));
   }
 
   // Avoid an empty bubble in the unlikely event that there is no network
   // information at all.
   if (!container->has_children()) {
-    container->AddChildView(CreateInfoBubbleLabel(bundle.GetLocalizedString(
-        IDS_ASH_STATUS_TRAY_NO_NETWORKS)));
+    container->AddChildView(CreateInfoBubbleLabel(
+        bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_NO_NETWORKS)));
   }
 
   return container;
@@ -585,8 +558,7 @@ void NetworkStateListDetailedView::CallRequestScan() {
 
 void NetworkStateListDetailedView::ToggleMobile() {
   NetworkStateHandler* handler = NetworkHandler::Get()->network_state_handler();
-  bool enabled =
-      handler->IsTechnologyEnabled(NetworkTypePattern::Mobile());
+  bool enabled = handler->IsTechnologyEnabled(NetworkTypePattern::Mobile());
   ui::NetworkConnect::Get()->SetTechnologyEnabled(NetworkTypePattern::Mobile(),
                                                   !enabled);
 }
@@ -622,11 +594,9 @@ void NetworkStateListDetailedView::UpdateViewForNetwork(
 
 views::Label* NetworkStateListDetailedView::CreateInfoLabel() {
   views::Label* label = new views::Label();
-  label->SetBorder(
-      views::Border::CreateEmptyBorder(ash::kTrayPopupPaddingBetweenItems,
-                                       ash::kTrayPopupPaddingHorizontal,
-                                       ash::kTrayPopupPaddingBetweenItems,
-                                       0));
+  label->SetBorder(views::Border::CreateEmptyBorder(
+      ash::kTrayPopupPaddingBetweenItems, ash::kTrayPopupPaddingHorizontal,
+      ash::kTrayPopupPaddingBetweenItems, 0));
   label->SetHorizontalAlignment(gfx::ALIGN_LEFT);
   label->SetEnabledColor(SkColorSetARGB(192, 0, 0, 0));
   return label;
diff --git a/ash/system/chromeos/network/network_state_list_detailed_view.h b/ash/system/chromeos/network/network_state_list_detailed_view.h
index 4400bec..b00f19af 100644
--- a/ash/system/chromeos/network/network_state_list_detailed_view.h
+++ b/ash/system/chromeos/network/network_state_list_detailed_view.h
@@ -38,31 +38,24 @@ class NetworkStateListDetailedView
       public ui::NetworkListDelegate,
       public base::SupportsWeakPtr<NetworkStateListDetailedView> {
  public:
-  enum ListType {
-    LIST_TYPE_NETWORK,
-    LIST_TYPE_VPN
-  };
+  enum ListType { LIST_TYPE_NETWORK, LIST_TYPE_VPN };
 
   NetworkStateListDetailedView(SystemTrayItem* owner,
                                ListType list_type,
                                user::LoginStatus login);
-  virtual ~NetworkStateListDetailedView();
+  ~NetworkStateListDetailedView() override;
 
   // Overridden from NetworkDetailedView:
-  virtual void Init() override;
-  virtual DetailedViewType GetViewType() const override;
-  virtual void ManagerChanged() override;
-  virtual void NetworkListChanged() override;
-  virtual void NetworkServiceChanged(
-      const chromeos::NetworkState* network) override;
+  void Init() override;
+  DetailedViewType GetViewType() const override;
+  void Update() override;
 
  protected:
   // Overridden from ButtonListener.
-  virtual void ButtonPressed(views::Button* sender,
-                             const ui::Event& event) override;
+  void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
   // Overridden from ViewClickListener.
-  virtual void OnViewClicked(views::View* sender) override;
+  void OnViewClicked(views::View* sender) override;
 
  private:
   class InfoBubble;
@@ -100,14 +93,13 @@ class NetworkStateListDetailedView
   void ToggleMobile();
 
   // ui::NetworkListDelegate:
-  virtual views::View* CreateViewForNetwork(
-      const ui::NetworkInfo& info) override;
-  virtual bool IsViewHovered(views::View* view) override;
-  virtual chromeos::NetworkTypePattern GetNetworkTypePattern() const override;
-  virtual void UpdateViewForNetwork(views::View* view,
-                                    const ui::NetworkInfo& info) override;
-  virtual views::Label* CreateInfoLabel() override;
-  virtual void RelayoutScrollList() override;
+  views::View* CreateViewForNetwork(const ui::NetworkInfo& info) override;
+  bool IsViewHovered(views::View* view) override;
+  chromeos::NetworkTypePattern GetNetworkTypePattern() const override;
+  void UpdateViewForNetwork(views::View* view,
+                            const ui::NetworkInfo& info) override;
+  views::Label* CreateInfoLabel() override;
+  void RelayoutScrollList() override;
 
   // Type of list (all networks or vpn)
   ListType list_type_;
diff --git a/ash/system/chromeos/network/tray_network.cc b/ash/system/chromeos/network/tray_network.cc
index a5c5570..b00e220 100644
--- a/ash/system/chromeos/network/tray_network.cc
+++ b/ash/system/chromeos/network/tray_network.cc
@@ -47,8 +47,7 @@ class NetworkTrayView : public TrayItemView,
                         public ui::network_icon::AnimationObserver {
  public:
   explicit NetworkTrayView(TrayNetwork* network_tray)
-      : TrayItemView(network_tray),
-        network_tray_(network_tray) {
+      : TrayItemView(network_tray), network_tray_(network_tray) {
     SetLayoutManager(
         new views::BoxLayout(views::BoxLayout::kHorizontal, 0, 0, 0));
 
@@ -58,13 +57,11 @@ class NetworkTrayView : public TrayItemView,
     UpdateNetworkStateHandlerIcon();
   }
 
-  virtual ~NetworkTrayView() {
+  ~NetworkTrayView() override {
     ui::network_icon::NetworkIconAnimation::GetInstance()->RemoveObserver(this);
   }
 
-  virtual const char* GetClassName() const override {
-    return "NetworkTrayView";
-  }
+  const char* GetClassName() const override { return "NetworkTrayView"; }
 
   void UpdateNetworkStateHandlerIcon() {
     NetworkStateHandler* handler =
@@ -85,31 +82,29 @@ class NetworkTrayView : public TrayItemView,
     const NetworkState* connected_network =
         handler->ConnectedNetworkByType(NetworkTypePattern::NonVirtual());
     if (connected_network) {
-      UpdateConnectionStatus(
-          base::UTF8ToUTF16(connected_network->name()), true);
+      UpdateConnectionStatus(base::UTF8ToUTF16(connected_network->name()),
+                             true);
     } else {
       UpdateConnectionStatus(base::string16(), false);
     }
   }
 
   void UpdateAlignment(ShelfAlignment alignment) {
-    SetLayoutManager(new views::BoxLayout(
-        alignment == SHELF_ALIGNMENT_BOTTOM ?
-            views::BoxLayout::kHorizontal : views::BoxLayout::kVertical,
-            0, 0, 0));
+    SetLayoutManager(new views::BoxLayout(alignment == SHELF_ALIGNMENT_BOTTOM
+                                              ? views::BoxLayout::kHorizontal
+                                              : views::BoxLayout::kVertical,
+                                          0, 0, 0));
     Layout();
   }
 
   // views::View override.
-  virtual void GetAccessibleState(ui::AXViewState* state) override {
+  void GetAccessibleState(ui::AXViewState* state) override {
     state->name = connection_status_string_;
     state->role = ui::AX_ROLE_BUTTON;
   }
 
   // ui::network_icon::AnimationObserver
-  virtual void NetworkIconChanged() override {
-    UpdateNetworkStateHandlerIcon();
-  }
+  void NetworkIconChanged() override { UpdateNetworkStateHandlerIcon(); }
 
  private:
   // Updates connection status and notifies accessibility event when necessary.
@@ -122,7 +117,7 @@ class NetworkTrayView : public TrayItemView,
     }
     if (new_connection_status_string != connection_status_string_) {
       connection_status_string_ = new_connection_status_string;
-      if(!connection_status_string_.empty())
+      if (!connection_status_string_.empty())
         NotifyAccessibilityEvent(ui::AX_EVENT_ALERT, true);
     }
   }
@@ -144,12 +139,11 @@ class NetworkDefaultView : public TrayItemMore,
                            public ui::network_icon::AnimationObserver {
  public:
   NetworkDefaultView(TrayNetwork* network_tray, bool show_more)
-      : TrayItemMore(network_tray, show_more),
-        network_tray_(network_tray) {
+      : TrayItemMore(network_tray, show_more), network_tray_(network_tray) {
     Update();
   }
 
-  virtual ~NetworkDefaultView() {
+  ~NetworkDefaultView() override {
     ui::network_icon::NetworkIconAnimation::GetInstance()->RemoveObserver(this);
   }
 
@@ -170,9 +164,7 @@ class NetworkDefaultView : public TrayItemMore,
   }
 
   // ui::network_icon::AnimationObserver
-  virtual void NetworkIconChanged() override {
-    Update();
-  }
+  void NetworkIconChanged() override { Update(); }
 
  private:
   TrayNetwork* network_tray_;
@@ -185,8 +177,7 @@ class NetworkWifiDetailedView : public NetworkDetailedView {
   explicit NetworkWifiDetailedView(SystemTrayItem* owner)
       : NetworkDetailedView(owner) {
     SetLayoutManager(new views::BoxLayout(views::BoxLayout::kHorizontal,
-                                          kTrayPopupPaddingHorizontal,
-                                          10,
+                                          kTrayPopupPaddingHorizontal, 10,
                                           kTrayPopupPaddingBetweenItems));
     image_view_ = new views::ImageView;
     AddChildView(image_view_);
@@ -199,58 +190,44 @@ class NetworkWifiDetailedView : public NetworkDetailedView {
     Update();
   }
 
-  virtual ~NetworkWifiDetailedView() {
-  }
+  ~NetworkWifiDetailedView() override {}
 
   // Overridden from NetworkDetailedView:
 
-  virtual void Init() override {
-  }
+  void Init() override {}
 
-  virtual NetworkDetailedView::DetailedViewType GetViewType() const override {
+  NetworkDetailedView::DetailedViewType GetViewType() const override {
     return NetworkDetailedView::WIFI_VIEW;
   }
 
-  virtual void ManagerChanged() override {
-    Update();
-  }
-
-  virtual void NetworkListChanged() override {
-    Update();
-  }
-
-  virtual void NetworkServiceChanged(
-      const chromeos::NetworkState* network) override {
-  }
-
- private:
-  virtual void Layout() override {
+  void Layout() override {
     // Center both views vertically.
     views::View::Layout();
-    image_view_->SetY(
-        (height() - image_view_->GetPreferredSize().height()) / 2);
-    label_view_->SetY(
-        (height() - label_view_->GetPreferredSize().height()) / 2);
+    image_view_->SetY((height() - image_view_->GetPreferredSize().height()) /
+                      2);
+    label_view_->SetY((height() - label_view_->GetPreferredSize().height()) /
+                      2);
   }
 
-  void Update() {
+  void Update() override {
     bool wifi_enabled =
         NetworkHandler::Get()->network_state_handler()->IsTechnologyEnabled(
             NetworkTypePattern::WiFi());
-    const int image_id = wifi_enabled ?
-        IDR_AURA_UBER_TRAY_WIFI_ENABLED : IDR_AURA_UBER_TRAY_WIFI_DISABLED;
+    const int image_id = wifi_enabled ? IDR_AURA_UBER_TRAY_WIFI_ENABLED
+                                      : IDR_AURA_UBER_TRAY_WIFI_DISABLED;
     ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
     image_view_->SetImage(bundle.GetImageNamed(image_id).ToImageSkia());
 
-    const int string_id = wifi_enabled ?
-        IDS_ASH_STATUS_TRAY_NETWORK_WIFI_ENABLED :
-        IDS_ASH_STATUS_TRAY_NETWORK_WIFI_DISABLED;
+    const int string_id = wifi_enabled
+                              ? IDS_ASH_STATUS_TRAY_NETWORK_WIFI_ENABLED
+                              : IDS_ASH_STATUS_TRAY_NETWORK_WIFI_DISABLED;
     label_view_->SetText(bundle.GetLocalizedString(string_id));
-    label_view_->SizeToFit(kTrayPopupMinWidth -
-        kTrayPopupPaddingHorizontal * 2 - kTrayPopupPaddingBetweenItems -
-        kTrayPopupDetailsIconWidth);
+    label_view_->SizeToFit(
+        kTrayPopupMinWidth - kTrayPopupPaddingHorizontal * 2 -
+        kTrayPopupPaddingBetweenItems - kTrayPopupDetailsIconWidth);
   }
 
+ private:
   views::ImageView* image_view_;
   views::Label* label_view_;
 
@@ -290,15 +267,15 @@ views::View* TrayNetwork::CreateDefaultView(user::LoginStatus status) {
   if (!chromeos::NetworkHandler::IsInitialized())
     return NULL;
   CHECK(tray_ != NULL);
-  default_ = new tray::NetworkDefaultView(
-      this, status != user::LOGGED_IN_LOCKED);
+  default_ =
+      new tray::NetworkDefaultView(this, status != user::LOGGED_IN_LOCKED);
   return default_;
 }
 
 views::View* TrayNetwork::CreateDetailedView(user::LoginStatus status) {
   CHECK(detailed_ == NULL);
   Shell::GetInstance()->metrics()->RecordUserMetricsAction(
-    ash::UMA_STATUS_AREA_DETAILED_NETWORK_VIEW);
+      ash::UMA_STATUS_AREA_DETAILED_NETWORK_VIEW);
   if (!chromeos::NetworkHandler::IsInitialized())
     return NULL;
   if (request_wifi_view_) {
@@ -344,35 +321,24 @@ void TrayNetwork::RequestToggleWifi() {
   NetworkStateHandler* handler = NetworkHandler::Get()->network_state_handler();
   bool enabled = handler->IsTechnologyEnabled(NetworkTypePattern::WiFi());
   Shell::GetInstance()->metrics()->RecordUserMetricsAction(
-      enabled ?
-      ash::UMA_STATUS_AREA_DISABLE_WIFI :
-      ash::UMA_STATUS_AREA_ENABLE_WIFI);
-  handler->SetTechnologyEnabled(NetworkTypePattern::WiFi(),
-                                !enabled,
+      enabled ? ash::UMA_STATUS_AREA_DISABLE_WIFI
+              : ash::UMA_STATUS_AREA_ENABLE_WIFI);
+  handler->SetTechnologyEnabled(NetworkTypePattern::WiFi(), !enabled,
                                 chromeos::network_handler::ErrorCallback());
 }
 
 void TrayNetwork::OnCaptivePortalDetected(
     const std::string& /* service_path */) {
-  NetworkStateChanged(false);
+  NetworkStateChanged();
 }
 
-void TrayNetwork::NetworkStateChanged(bool list_changed) {
+void TrayNetwork::NetworkStateChanged() {
   if (tray_)
     tray_->UpdateNetworkStateHandlerIcon();
   if (default_)
     default_->Update();
-  if (detailed_) {
-    if (list_changed)
-      detailed_->NetworkListChanged();
-    else
-      detailed_->ManagerChanged();
-  }
-}
-
-void TrayNetwork::NetworkServiceChanged(const chromeos::NetworkState* network) {
   if (detailed_)
-    detailed_->NetworkServiceChanged(network);
+    detailed_->Update();
 }
 
 }  // namespace ash
diff --git a/ash/system/chromeos/network/tray_network.h b/ash/system/chromeos/network/tray_network.h
index 407b64e..72c0a09 100644
--- a/ash/system/chromeos/network/tray_network.h
+++ b/ash/system/chromeos/network/tray_network.h
@@ -31,32 +31,28 @@ class TrayNetwork : public SystemTrayItem,
                     public TrayNetworkStateObserver::Delegate {
  public:
   explicit TrayNetwork(SystemTray* system_tray);
-  virtual ~TrayNetwork();
+  ~TrayNetwork() override;
 
   tray::NetworkDetailedView* detailed() { return detailed_; }
 
   // SystemTrayItem
-  virtual views::View* CreateTrayView(user::LoginStatus status) override;
-  virtual views::View* CreateDefaultView(user::LoginStatus status) override;
-  virtual views::View* CreateDetailedView(user::LoginStatus status) override;
-  virtual void DestroyTrayView() override;
-  virtual void DestroyDefaultView() override;
-  virtual void DestroyDetailedView() override;
-  virtual void UpdateAfterLoginStatusChange(user::LoginStatus status) override;
-  virtual void UpdateAfterShelfAlignmentChange(
-      ShelfAlignment alignment) override;
+  views::View* CreateTrayView(user::LoginStatus status) override;
+  views::View* CreateDefaultView(user::LoginStatus status) override;
+  views::View* CreateDetailedView(user::LoginStatus status) override;
+  void DestroyTrayView() override;
+  void DestroyDefaultView() override;
+  void DestroyDetailedView() override;
+  void UpdateAfterLoginStatusChange(user::LoginStatus status) override;
+  void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override;
 
   // NetworkObserver
-  virtual void RequestToggleWifi() override;
+  void RequestToggleWifi() override;
 
   // NetworkPortalDetectorObserver
-  virtual void OnCaptivePortalDetected(
-      const std::string& service_path) override;
+  void OnCaptivePortalDetected(const std::string& service_path) override;
 
   // TrayNetworkStateObserver::Delegate
-  virtual void NetworkStateChanged(bool list_changed) override;
-  virtual void NetworkServiceChanged(
-      const chromeos::NetworkState* network) override;
+  void NetworkStateChanged() override;
 
  private:
   tray::NetworkTrayView* tray_;
diff --git a/ash/system/chromeos/network/tray_network_state_observer.cc b/ash/system/chromeos/network/tray_network_state_observer.cc
index 4239be2..c23279e 100644
--- a/ash/system/chromeos/network/tray_network_state_observer.cc
+++ b/ash/system/chromeos/network/tray_network_state_observer.cc
@@ -7,45 +7,60 @@
 #include <set>
 #include <string>
 
+#include "ash/system/tray/system_tray.h"
 #include "base/location.h"
+#include "chromeos/device_event_log.h"
 #include "chromeos/network/network_state.h"
 #include "chromeos/network/network_state_handler.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 #include "ui/chromeos/network/network_icon.h"
+#include "ui/compositor/scoped_animation_duration_scale_mode.h"
 
 using chromeos::NetworkHandler;
 
+namespace {
+
+const int kUpdateFrequencyMs = 1000;
+
+}  // namespace
+
 namespace ash {
 
 TrayNetworkStateObserver::TrayNetworkStateObserver(Delegate* delegate)
-    : delegate_(delegate) {
+    : delegate_(delegate),
+      purge_icons_(false),
+      update_frequency_(kUpdateFrequencyMs) {
+  if (ui::ScopedAnimationDurationScaleMode::duration_scale_mode() !=
+      ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION) {
+    update_frequency_ = 0;  // Send updates immediately for tests.
+  }
   if (NetworkHandler::IsInitialized()) {
-    NetworkHandler::Get()->network_state_handler()->AddObserver(
-        this, FROM_HERE);
+    NetworkHandler::Get()->network_state_handler()->AddObserver(this,
+                                                                FROM_HERE);
   }
 }
 
 TrayNetworkStateObserver::~TrayNetworkStateObserver() {
   if (NetworkHandler::IsInitialized()) {
-    NetworkHandler::Get()->network_state_handler()->RemoveObserver(
-        this, FROM_HERE);
+    NetworkHandler::Get()->network_state_handler()->RemoveObserver(this,
+                                                                   FROM_HERE);
   }
 }
 
 void TrayNetworkStateObserver::NetworkListChanged() {
-  delegate_->NetworkStateChanged(true);
-  ui::network_icon::PurgeNetworkIconCache();
+  purge_icons_ = true;
+  SignalUpdate();
 }
 
 void TrayNetworkStateObserver::DeviceListChanged() {
-  delegate_->NetworkStateChanged(false);
+  SignalUpdate();
 }
 
 // Any change to the Default (primary connected) network, including Strength
 // changes, should trigger a NetworkStateChanged update.
 void TrayNetworkStateObserver::DefaultNetworkChanged(
     const chromeos::NetworkState* network) {
-  delegate_->NetworkStateChanged(true);
+  SignalUpdate();
 }
 
 // Any change to the Connection State should trigger a NetworkStateChanged
@@ -53,7 +68,7 @@ void TrayNetworkStateObserver::DefaultNetworkChanged(
 // connected.
 void TrayNetworkStateObserver::NetworkConnectionStateChanged(
     const chromeos::NetworkState* network) {
-  delegate_->NetworkStateChanged(true);
+  SignalUpdate();
 }
 
 // This tracks Strength and other property changes for all networks. It will
@@ -61,13 +76,22 @@ void TrayNetworkStateObserver::NetworkConnectionStateChanged(
 // changes.
 void TrayNetworkStateObserver::NetworkPropertiesUpdated(
     const chromeos::NetworkState* network) {
-  if (network ==
-      NetworkHandler::Get()->network_state_handler()->DefaultNetwork()) {
-    // Trigger NetworkStateChanged in case the Strength property of the
-    // Default network changed.
-    delegate_->NetworkStateChanged(true);
+  SignalUpdate();
+}
+
+void TrayNetworkStateObserver::SignalUpdate() {
+  if (timer_.IsRunning())
+    return;
+  timer_.Start(FROM_HERE, base::TimeDelta::FromMilliseconds(update_frequency_),
+               this, &TrayNetworkStateObserver::SendNetworkStateChanged);
+}
+
+void TrayNetworkStateObserver::SendNetworkStateChanged() {
+  delegate_->NetworkStateChanged();
+  if (purge_icons_) {
+    ui::network_icon::PurgeNetworkIconCache();
+    purge_icons_ = false;
   }
-  delegate_->NetworkServiceChanged(network);
 }
 
 }  // namespace ash
diff --git a/ash/system/chromeos/network/tray_network_state_observer.h b/ash/system/chromeos/network/tray_network_state_observer.h
index f062a6b..af9bed6 100644
--- a/ash/system/chromeos/network/tray_network_state_observer.h
+++ b/ash/system/chromeos/network/tray_network_state_observer.h
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "base/compiler_specific.h"
+#include "base/timer/timer.h"
 #include "chromeos/network/network_state_handler_observer.h"
 
 namespace ash {
@@ -16,13 +17,9 @@ class TrayNetworkStateObserver : public chromeos::NetworkStateHandlerObserver {
  public:
   class Delegate {
    public:
-    // Called when the network state may have changed. If |list_changed| is
-    // true then the list of networks may have changed.
-    virtual void NetworkStateChanged(bool list_changed) = 0;
-
-    // Called when the properties for |network| may have been updated.
-    virtual void NetworkServiceChanged(
-        const chromeos::NetworkState* network) = 0;
+    // Called when any interesting network changes occur. The frequency of this
+    // event is limited to kUpdateFrequencyMs.
+    virtual void NetworkStateChanged() = 0;
 
    protected:
     virtual ~Delegate() {}
@@ -30,21 +27,34 @@ class TrayNetworkStateObserver : public chromeos::NetworkStateHandlerObserver {
 
   explicit TrayNetworkStateObserver(Delegate* delegate);
 
-  virtual ~TrayNetworkStateObserver();
+  ~TrayNetworkStateObserver() override;
 
   // NetworkStateHandlerObserver overrides.
-  virtual void NetworkListChanged() override;
-  virtual void DeviceListChanged() override;
-  virtual void DefaultNetworkChanged(
-      const chromeos::NetworkState* network) override;
-  virtual void NetworkConnectionStateChanged(
-      const chromeos::NetworkState* network) override;
-  virtual void NetworkPropertiesUpdated(
+  void NetworkListChanged() override;
+  void DeviceListChanged() override;
+  void DefaultNetworkChanged(const chromeos::NetworkState* network) override;
+  void NetworkConnectionStateChanged(
       const chromeos::NetworkState* network) override;
+  void NetworkPropertiesUpdated(const chromeos::NetworkState* network) override;
 
  private:
+  void SignalUpdate();
+  void SendNetworkStateChanged();
+
+  // Unowned Delegate pointer (must outlive this instance).
   Delegate* delegate_;
 
+  // Set to true when we should purge stale icons in the cache.
+  bool purge_icons_;
+
+  // Frequency at which to push NetworkStateChanged updates. This avoids
+  // unnecessarily frequent UI updates (which can be expensive). We set this
+  // to 0 for tests to eliminate timing variance.
+  int update_frequency_;
+
+  // Timer used to limit the frequency of NetworkStateChanged updates.
+  base::OneShotTimer<TrayNetworkStateObserver> timer_;
+
   DISALLOW_COPY_AND_ASSIGN(TrayNetworkStateObserver);
 };
 
diff --git a/ash/system/chromeos/network/tray_vpn.cc b/ash/system/chromeos/network/tray_vpn.cc
index 545a5ba..0d4cbea 100644
--- a/ash/system/chromeos/network/tray_vpn.cc
+++ b/ash/system/chromeos/network/tray_vpn.cc
@@ -13,6 +13,7 @@
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_item_more.h"
 #include "ash/system/tray/tray_popup_label_button.h"
+#include "chromeos/device_event_log.h"
 #include "chromeos/network/network_state.h"
 #include "chromeos/network/network_state_handler.h"
 #include "grit/ash_strings.h"
@@ -38,7 +39,7 @@ class VpnDefaultView : public TrayItemMore,
     Update();
   }
 
-  virtual ~VpnDefaultView() {
+  ~VpnDefaultView() override {
     ui::network_icon::NetworkIconAnimation::GetInstance()->RemoveObserver(this);
   }
 
@@ -67,9 +68,7 @@ class VpnDefaultView : public TrayItemMore,
   }
 
   // ui::network_icon::AnimationObserver
-  virtual void NetworkIconChanged() override {
-    Update();
-  }
+  void NetworkIconChanged() override { Update(); }
 
  private:
   void GetNetworkStateHandlerImageAndLabel(gfx::ImageSkia* image,
@@ -83,8 +82,8 @@ class VpnDefaultView : public TrayItemMore,
       *image = ui::network_icon::GetImageForDisconnectedNetwork(
           ui::network_icon::ICON_TYPE_DEFAULT_VIEW, shill::kTypeVPN);
       if (label) {
-        *label = l10n_util::GetStringUTF16(
-            IDS_ASH_STATUS_TRAY_VPN_DISCONNECTED);
+        *label =
+            l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_VPN_DISCONNECTED);
       }
       *animating = false;
       return;
@@ -104,9 +103,7 @@ class VpnDefaultView : public TrayItemMore,
 }  // namespace tray
 
 TrayVPN::TrayVPN(SystemTray* system_tray)
-    : SystemTrayItem(system_tray),
-      default_(NULL),
-      detailed_(NULL) {
+    : SystemTrayItem(system_tray), default_(NULL), detailed_(NULL) {
   network_state_observer_.reset(new TrayNetworkStateObserver(this));
 }
 
@@ -166,20 +163,11 @@ void TrayVPN::UpdateAfterLoginStatusChange(user::LoginStatus status) {
 void TrayVPN::UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) {
 }
 
-void TrayVPN::NetworkStateChanged(bool list_changed) {
+void TrayVPN::NetworkStateChanged() {
   if (default_)
     default_->Update();
-  if (detailed_) {
-    if (list_changed)
-      detailed_->NetworkListChanged();
-    else
-      detailed_->ManagerChanged();
-  }
-}
-
-void TrayVPN::NetworkServiceChanged(const chromeos::NetworkState* network) {
   if (detailed_)
-    detailed_->NetworkServiceChanged(network);
+    detailed_->Update();
 }
 
 }  // namespace ash
diff --git a/ash/system/chromeos/network/tray_vpn.h b/ash/system/chromeos/network/tray_vpn.h
index 74d7aaa..9b56c82 100644
--- a/ash/system/chromeos/network/tray_vpn.h
+++ b/ash/system/chromeos/network/tray_vpn.h
@@ -22,23 +22,20 @@ class TrayVPN : public SystemTrayItem,
                 public TrayNetworkStateObserver::Delegate {
  public:
   explicit TrayVPN(SystemTray* system_tray);
-  virtual ~TrayVPN();
+  ~TrayVPN() override;
 
   // SystemTrayItem
-  virtual views::View* CreateTrayView(user::LoginStatus status) override;
-  virtual views::View* CreateDefaultView(user::LoginStatus status) override;
-  virtual views::View* CreateDetailedView(user::LoginStatus status) override;
-  virtual void DestroyTrayView() override;
-  virtual void DestroyDefaultView() override;
-  virtual void DestroyDetailedView() override;
-  virtual void UpdateAfterLoginStatusChange(user::LoginStatus status) override;
-  virtual void UpdateAfterShelfAlignmentChange(
-      ShelfAlignment alignment) override;
+  views::View* CreateTrayView(user::LoginStatus status) override;
+  views::View* CreateDefaultView(user::LoginStatus status) override;
+  views::View* CreateDetailedView(user::LoginStatus status) override;
+  void DestroyTrayView() override;
+  void DestroyDefaultView() override;
+  void DestroyDetailedView() override;
+  void UpdateAfterLoginStatusChange(user::LoginStatus status) override;
+  void UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) override;
 
   // TrayNetworkStateObserver::Delegate
-  virtual void NetworkStateChanged(bool list_changed) override;
-  virtual void NetworkServiceChanged(
-      const chromeos::NetworkState* network) override;
+  void NetworkStateChanged() override;
 
  private:
   tray::VpnDefaultView* default_;