Fourth batch adding real histogram values for extension events.

This is the last batch of trivial replacements of the form
DispatchEvent(kFooEvent) --> DispatchEvent(events::FOO_EVENT, kFooEvent).

The remaining 15 or so files are less trivial, but there are only 15.

BUG=503402
R=rdevlin.cronin@chromium.org, isherman@chromium.org

Review URL: https://codereview.chromium.org/1240913002

Cr-Commit-Position: refs/heads/master@{#339209}

16 files changed, 96 insertions, 80 deletions

diff --git a/extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.cc b/extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.cc
index 6884735..d252f16 100644
--- a/extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.cc
+++ b/extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.cc
@@ -866,8 +866,9 @@ void BluetoothLowEnergyEventRouter::GattServiceRemoved(
 
   scoped_ptr<base::ListValue> args =
       apibtle::OnServiceRemoved::Create(api_service);
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, apibtle::OnServiceRemoved::kEventName, args.Pass()));
+  scoped_ptr<Event> event(
+      new Event(events::BLUETOOTH_LOW_ENERGY_ON_SERVICE_REMOVED,
+                apibtle::OnServiceRemoved::kEventName, args.Pass()));
   EventRouter::Get(browser_context_)->BroadcastEvent(event.Pass());
 }
 
@@ -887,8 +888,9 @@ void BluetoothLowEnergyEventRouter::GattDiscoveryCompleteForService(
 
   scoped_ptr<base::ListValue> args =
       apibtle::OnServiceAdded::Create(api_service);
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, apibtle::OnServiceAdded::kEventName, args.Pass()));
+  scoped_ptr<Event> event(
+      new Event(events::BLUETOOTH_LOW_ENERGY_ON_SERVICE_ADDED,
+                apibtle::OnServiceAdded::kEventName, args.Pass()));
   EventRouter::Get(browser_context_)->BroadcastEvent(event.Pass());
 }
 
@@ -906,8 +908,8 @@ void BluetoothLowEnergyEventRouter::GattServiceChanged(
   PopulateService(service, &api_service);
 
   DispatchEventToExtensionsWithPermission(
-      apibtle::OnServiceChanged::kEventName,
-      service->GetUUID(),
+      events::BLUETOOTH_LOW_ENERGY_ON_SERVICE_CHANGED,
+      apibtle::OnServiceChanged::kEventName, service->GetUUID(),
       "" /* characteristic_id */,
       apibtle::OnServiceChanged::Create(api_service));
 }
@@ -1014,10 +1016,9 @@ void BluetoothLowEnergyEventRouter::GattCharacteristicValueChanged(
   args->Append(apibtle::CharacteristicToValue(&api_characteristic).release());
 
   DispatchEventToExtensionsWithPermission(
-      apibtle::OnCharacteristicValueChanged::kEventName,
-      service->GetUUID(),
-      characteristic->GetIdentifier(),
-      args.Pass());
+      events::BLUETOOTH_LOW_ENERGY_ON_CHARACTERISTIC_VALUE_CHANGED,
+      apibtle::OnCharacteristicValueChanged::kEventName, service->GetUUID(),
+      characteristic->GetIdentifier(), args.Pass());
 }
 
 void BluetoothLowEnergyEventRouter::GattDescriptorValueChanged(
@@ -1045,9 +1046,9 @@ void BluetoothLowEnergyEventRouter::GattDescriptorValueChanged(
   args->Append(apibtle::DescriptorToValue(&api_descriptor).release());
 
   DispatchEventToExtensionsWithPermission(
+      events::BLUETOOTH_LOW_ENERGY_ON_DESCRIPTOR_VALUE_CHANGED,
       apibtle::OnDescriptorValueChanged::kEventName,
-      characteristic->GetService()->GetUUID(),
-      "" /* characteristic_id */,
+      characteristic->GetService()->GetUUID(), "" /* characteristic_id */,
       args.Pass());
 }
 
@@ -1116,6 +1117,7 @@ void BluetoothLowEnergyEventRouter::InitializeIdentifierMappings() {
 }
 
 void BluetoothLowEnergyEventRouter::DispatchEventToExtensionsWithPermission(
+    events::HistogramValue histogram_value,
     const std::string& event_name,
     const device::BluetoothUUID& uuid,
     const std::string& characteristic_id,
@@ -1161,7 +1163,7 @@ void BluetoothLowEnergyEventRouter::DispatchEventToExtensionsWithPermission(
     // Send the event.
     scoped_ptr<base::ListValue> args_copy(args->DeepCopy());
     scoped_ptr<Event> event(
-        new Event(events::UNKNOWN, event_name, args_copy.Pass()));
+        new Event(histogram_value, event_name, args_copy.Pass()));
     EventRouter::Get(browser_context_)->DispatchEventToExtension(
         extension_id, event.Pass());
   }
diff --git a/extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.h b/extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.h
index f265505..a27d36b 100644
--- a/extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.h
+++ b/extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.h
@@ -17,6 +17,7 @@
 #include "device/bluetooth/bluetooth_adapter.h"
 #include "device/bluetooth/bluetooth_device.h"
 #include "device/bluetooth/bluetooth_gatt_service.h"
+#include "extensions/browser/extension_event_histogram_value.h"
 #include "extensions/common/api/bluetooth_low_energy.h"
 
 namespace base {
@@ -286,6 +287,7 @@ class BluetoothLowEnergyEventRouter
   // should be the instance ID of the involved characteristic. Otherwise, an
   // empty string should be passed.
   void DispatchEventToExtensionsWithPermission(
+      events::HistogramValue histogram_value,
       const std::string& event_name,
       const device::BluetoothUUID& uuid,
       const std::string& characteristic_id,
diff --git a/extensions/browser/api/bluetooth_socket/bluetooth_socket_event_dispatcher.cc b/extensions/browser/api/bluetooth_socket/bluetooth_socket_event_dispatcher.cc
index 03f0be8..ee8a641 100644
--- a/extensions/browser/api/bluetooth_socket/bluetooth_socket_event_dispatcher.cc
+++ b/extensions/browser/api/bluetooth_socket/bluetooth_socket_event_dispatcher.cc
@@ -194,8 +194,9 @@ void BluetoothSocketEventDispatcher::ReceiveCallback(
   receive_info.data.assign(io_buffer->data(), io_buffer->data() + bytes_read);
   scoped_ptr<base::ListValue> args =
       bluetooth_socket::OnReceive::Create(receive_info);
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, bluetooth_socket::OnReceive::kEventName, args.Pass()));
+  scoped_ptr<Event> event(new Event(events::BLUETOOTH_SOCKET_ON_RECEIVE,
+                                    bluetooth_socket::OnReceive::kEventName,
+                                    args.Pass()));
   PostEvent(params, event.Pass());
 
   // Post a task to delay the read until the socket is available, as
@@ -229,8 +230,8 @@ void BluetoothSocketEventDispatcher::ReceiveErrorCallback(
   scoped_ptr<base::ListValue> args =
       bluetooth_socket::OnReceiveError::Create(receive_error_info);
   scoped_ptr<Event> event(
-      new Event(events::UNKNOWN, bluetooth_socket::OnReceiveError::kEventName,
-                args.Pass()));
+      new Event(events::BLUETOOTH_SOCKET_ON_RECEIVE_ERROR,
+                bluetooth_socket::OnReceiveError::kEventName, args.Pass()));
   PostEvent(params, event.Pass());
 
   // Since we got an error, the socket is now "paused" until the application
@@ -290,8 +291,9 @@ void BluetoothSocketEventDispatcher::AcceptCallback(
   accept_info.client_socket_id = client_socket_id;
   scoped_ptr<base::ListValue> args =
       bluetooth_socket::OnAccept::Create(accept_info);
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, bluetooth_socket::OnAccept::kEventName, args.Pass()));
+  scoped_ptr<Event> event(new Event(events::BLUETOOTH_SOCKET_ON_ACCEPT,
+                                    bluetooth_socket::OnAccept::kEventName,
+                                    args.Pass()));
   PostEvent(params, event.Pass());
 
   // Post a task to delay the accept until the socket is available, as
@@ -324,7 +326,7 @@ void BluetoothSocketEventDispatcher::AcceptErrorCallback(
   accept_error_info.error = MapAcceptErrorReason(error_reason);
   scoped_ptr<base::ListValue> args =
       bluetooth_socket::OnAcceptError::Create(accept_error_info);
-  scoped_ptr<Event> event(new Event(events::UNKNOWN,
+  scoped_ptr<Event> event(new Event(events::BLUETOOTH_SOCKET_ON_ACCEPT_ERROR,
                                     bluetooth_socket::OnAcceptError::kEventName,
                                     args.Pass()));
   PostEvent(params, event.Pass());
diff --git a/extensions/browser/api/cast_channel/cast_channel_api.cc b/extensions/browser/api/cast_channel/cast_channel_api.cc
index bc7d12f..3ec0b63 100644
--- a/extensions/browser/api/cast_channel/cast_channel_api.cc
+++ b/extensions/browser/api/cast_channel/cast_channel_api.cc
@@ -512,8 +512,8 @@ void CastChannelOpenFunction::CastMessageHandler::OnError(
 
   scoped_ptr<base::ListValue> results =
       OnError::Create(channel_info, error_info);
-  scoped_ptr<Event> event(
-      new Event(events::UNKNOWN, OnError::kEventName, results.Pass()));
+  scoped_ptr<Event> event(new Event(events::CAST_CHANNEL_ON_ERROR,
+                                    OnError::kEventName, results.Pass()));
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(ui_dispatch_cb_, socket_->owner_extension_id(),
@@ -533,8 +533,8 @@ void CastChannelOpenFunction::CastMessageHandler::OnMessage(
 
   scoped_ptr<base::ListValue> results =
       OnMessage::Create(channel_info, message_info);
-  scoped_ptr<Event> event(
-      new Event(events::UNKNOWN, OnMessage::kEventName, results.Pass()));
+  scoped_ptr<Event> event(new Event(events::CAST_CHANNEL_ON_MESSAGE,
+                                    OnMessage::kEventName, results.Pass()));
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(ui_dispatch_cb_, socket_->owner_extension_id(),
diff --git a/extensions/browser/api/idle/idle_manager.cc b/extensions/browser/api/idle/idle_manager.cc
index a221436..d4a1ff9 100644
--- a/extensions/browser/api/idle/idle_manager.cc
+++ b/extensions/browser/api/idle/idle_manager.cc
@@ -49,8 +49,9 @@ void DefaultEventDelegate::OnStateChanged(const std::string& extension_id,
                                           ui::IdleState new_state) {
   scoped_ptr<base::ListValue> args(new base::ListValue());
   args->Append(IdleManager::CreateIdleValue(new_state));
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, idle::OnStateChanged::kEventName, args.Pass()));
+  scoped_ptr<Event> event(new Event(events::IDLE_ON_STATE_CHANGED,
+                                    idle::OnStateChanged::kEventName,
+                                    args.Pass()));
   event->restrict_to_browser_context = context_;
   EventRouter::Get(context_)
       ->DispatchEventToExtension(extension_id, event.Pass());
diff --git a/extensions/browser/api/networking_config/networking_config_service.cc b/extensions/browser/api/networking_config/networking_config_service.cc
index 55c90b43..d5d9156 100644
--- a/extensions/browser/api/networking_config/networking_config_service.cc
+++ b/extensions/browser/api/networking_config/networking_config_service.cc
@@ -137,9 +137,8 @@ void NetworkingConfigService::OnGotProperties(
     const base::Closure& authentication_callback,
     const std::string& service_path,
     const base::DictionaryValue& onc_network_config) {
-  authentication_result_ =
-      extensions::NetworkingConfigService::AuthenticationResult(
-          std::string(), guid, extensions::NetworkingConfigService::NOTRY);
+  authentication_result_ = NetworkingConfigService::AuthenticationResult(
+      std::string(), guid, NetworkingConfigService::NOTRY);
   authentication_callback_ = authentication_callback;
 
   // Try to extract |bssid| field.
@@ -183,9 +182,8 @@ scoped_ptr<Event> NetworkingConfigService::CreatePortalDetectedEventAndDispatch(
     return nullptr;
 
   // Populate the NetworkInfo object.
-  extensions::core_api::networking_config::NetworkInfo network_info;
-  network_info.type =
-      extensions::core_api::networking_config::NETWORK_TYPE_WIFI;
+  core_api::networking_config::NetworkInfo network_info;
+  network_info.type = core_api::networking_config::NETWORK_TYPE_WIFI;
   const std::vector<uint8_t>& raw_ssid = network->raw_ssid();
   std::string hex_ssid =
       base::HexEncode(vector_as_array(&raw_ssid), raw_ssid.size());
@@ -195,12 +193,12 @@ scoped_ptr<Event> NetworkingConfigService::CreatePortalDetectedEventAndDispatch(
   if (bssid)
     network_info.bssid.reset(new std::string(*bssid));
   scoped_ptr<base::ListValue> results =
-      extensions::core_api::networking_config::OnCaptivePortalDetected::Create(
+      core_api::networking_config::OnCaptivePortalDetected::Create(
           network_info);
-  scoped_ptr<Event> event(new Event(events::UNKNOWN,
-                                    extensions::core_api::networking_config::
-                                        OnCaptivePortalDetected::kEventName,
-                                    results.Pass()));
+  scoped_ptr<Event> event(new Event(
+      events::NETWORKING_CONFIG_ON_CAPTIVE_PORTAL_DETECTED,
+      core_api::networking_config::OnCaptivePortalDetected::kEventName,
+      results.Pass()));
   return event.Pass();
 }
 
diff --git a/extensions/browser/api/networking_private/networking_private_event_router_chromeos.cc b/extensions/browser/api/networking_private/networking_private_event_router_chromeos.cc
index 9ecbd9c..2dabfdb 100644
--- a/extensions/browser/api/networking_private/networking_private_event_router_chromeos.cc
+++ b/extensions/browser/api/networking_private/networking_private_event_router_chromeos.cc
@@ -170,7 +170,7 @@ void NetworkingPrivateEventRouterImpl::NetworkListChanged() {
   scoped_ptr<base::ListValue> args(
       core_api::networking_private::OnNetworkListChanged::Create(changes));
   scoped_ptr<Event> extension_event(
-      new Event(events::UNKNOWN,
+      new Event(events::NETWORKING_PRIVATE_ON_NETWORK_LIST_CHANGED,
                 core_api::networking_private::OnNetworkListChanged::kEventName,
                 args.Pass()));
   event_router->BroadcastEvent(extension_event.Pass());
@@ -186,7 +186,7 @@ void NetworkingPrivateEventRouterImpl::DeviceListChanged() {
   scoped_ptr<base::ListValue> args(
       core_api::networking_private::OnDeviceStateListChanged::Create());
   scoped_ptr<Event> extension_event(new Event(
-      events::UNKNOWN,
+      events::NETWORKING_PRIVATE_ON_DEVICE_STATE_LIST_CHANGED,
       core_api::networking_private::OnDeviceStateListChanged::kEventName,
       args.Pass()));
   event_router->BroadcastEvent(extension_event.Pass());
@@ -206,7 +206,7 @@ void NetworkingPrivateEventRouterImpl::NetworkPropertiesUpdated(
       core_api::networking_private::OnNetworksChanged::Create(
           std::vector<std::string>(1, network->guid())));
   scoped_ptr<Event> extension_event(
-      new Event(events::UNKNOWN,
+      new Event(events::NETWORKING_PRIVATE_ON_NETWORKS_CHANGED,
                 core_api::networking_private::OnNetworksChanged::kEventName,
                 args.Pass()));
   event_router->BroadcastEvent(extension_event.Pass());
@@ -270,7 +270,7 @@ void NetworkingPrivateEventRouterImpl::OnPortalDetectionCompleted(
       core_api::networking_private::OnPortalDetectionCompleted::Create(path,
                                                                        status));
   scoped_ptr<Event> extension_event(new Event(
-      events::UNKNOWN,
+      events::NETWORKING_PRIVATE_ON_PORTAL_DETECTION_COMPLETED,
       core_api::networking_private::OnPortalDetectionCompleted::kEventName,
       args.Pass()));
   event_router->BroadcastEvent(extension_event.Pass());
diff --git a/extensions/browser/api/networking_private/networking_private_event_router_nonchromeos.cc b/extensions/browser/api/networking_private/networking_private_event_router_nonchromeos.cc
index dd04ea5..252c6a3 100644
--- a/extensions/browser/api/networking_private/networking_private_event_router_nonchromeos.cc
+++ b/extensions/browser/api/networking_private/networking_private_event_router_nonchromeos.cc
@@ -136,10 +136,10 @@ void NetworkingPrivateEventRouterImpl::OnNetworksChangedEvent(
     return;
   scoped_ptr<base::ListValue> args(
       core_api::networking_private::OnNetworksChanged::Create(network_guids));
-  scoped_ptr<extensions::Event> netchanged_event(new extensions::Event(
-      extensions::events::UNKNOWN,
-      core_api::networking_private::OnNetworksChanged::kEventName,
-      args.Pass()));
+  scoped_ptr<Event> netchanged_event(
+      new Event(events::NETWORKING_PRIVATE_ON_NETWORKS_CHANGED,
+                core_api::networking_private::OnNetworksChanged::kEventName,
+                args.Pass()));
   event_router->BroadcastEvent(netchanged_event.Pass());
 }
 
@@ -151,10 +151,10 @@ void NetworkingPrivateEventRouterImpl::OnNetworkListChangedEvent(
   scoped_ptr<base::ListValue> args(
       core_api::networking_private::OnNetworkListChanged::Create(
           network_guids));
-  scoped_ptr<extensions::Event> netlistchanged_event(new extensions::Event(
-      extensions::events::UNKNOWN,
-      core_api::networking_private::OnNetworkListChanged::kEventName,
-      args.Pass()));
+  scoped_ptr<Event> netlistchanged_event(
+      new Event(events::NETWORKING_PRIVATE_ON_NETWORK_LIST_CHANGED,
+                core_api::networking_private::OnNetworkListChanged::kEventName,
+                args.Pass()));
   event_router->BroadcastEvent(netlistchanged_event.Pass());
 }
 
diff --git a/extensions/browser/api/printer_provider/printer_provider_api.cc b/extensions/browser/api/printer_provider/printer_provider_api.cc
index 5b8be0f..82e3f31 100644
--- a/extensions/browser/api/printer_provider/printer_provider_api.cc
+++ b/extensions/browser/api/printer_provider/printer_provider_api.cc
@@ -527,7 +527,7 @@ void PrinterProviderAPIImpl::DispatchGetPrintersRequested(
   internal_args->AppendInteger(request_id);
 
   scoped_ptr<Event> event(
-      new Event(events::UNKNOWN,
+      new Event(events::PRINTER_PROVIDER_ON_GET_PRINTERS_REQUESTED,
                 core_api::printer_provider::OnGetPrintersRequested::kEventName,
                 internal_args.Pass()));
   // This callback is called synchronously during |BroadcastEvent|, so
@@ -566,7 +566,7 @@ void PrinterProviderAPIImpl::DispatchGetCapabilityRequested(
   internal_args->AppendString(internal_printer_id);
 
   scoped_ptr<Event> event(new Event(
-      events::UNKNOWN,
+      events::PRINTER_PROVIDER_ON_GET_CAPABILITY_REQUESTED,
       core_api::printer_provider::OnGetCapabilityRequested::kEventName,
       internal_args.Pass()));
 
@@ -614,9 +614,10 @@ void PrinterProviderAPIImpl::DispatchPrintRequested(
   // custom bindings.
   internal_args->AppendInteger(request_id);
   internal_args->Append(print_job.ToValue().release());
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, core_api::printer_provider::OnPrintRequested::kEventName,
-      internal_args.Pass()));
+  scoped_ptr<Event> event(
+      new Event(events::PRINTER_PROVIDER_ON_PRINT_REQUESTED,
+                core_api::printer_provider::OnPrintRequested::kEventName,
+                internal_args.Pass()));
   event_router->DispatchEventToExtension(extension_id, event.Pass());
 }
 
@@ -655,7 +656,7 @@ void PrinterProviderAPIImpl::DispatchGetUsbPrinterInfoRequested(
   internal_args->AppendInteger(request_id);
   internal_args->Append(usb_device.ToValue().release());
   scoped_ptr<Event> event(new Event(
-      events::UNKNOWN,
+      events::PRINTER_PROVIDER_ON_GET_USB_PRINTER_INFO_REQUESTED,
       core_api::printer_provider::OnGetUsbPrinterInfoRequested::kEventName,
       internal_args.Pass()));
   event_router->DispatchEventToExtension(extension_id, event.Pass());
diff --git a/extensions/browser/api/runtime/runtime_api.cc b/extensions/browser/api/runtime/runtime_api.cc
index d69d518..1766003 100644
--- a/extensions/browser/api/runtime/runtime_api.cc
+++ b/extensions/browser/api/runtime/runtime_api.cc
@@ -105,8 +105,9 @@ void DispatchOnStartupEventImpl(BrowserContext* browser_context,
   }
 
   scoped_ptr<base::ListValue> event_args(new base::ListValue());
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, runtime::OnStartup::kEventName, event_args.Pass()));
+  scoped_ptr<Event> event(new Event(events::RUNTIME_ON_STARTUP,
+                                    runtime::OnStartup::kEventName,
+                                    event_args.Pass()));
   EventRouter::Get(browser_context)
       ->DispatchEventToExtension(extension_id, event.Pass());
 }
@@ -307,8 +308,9 @@ void RuntimeEventRouter::DispatchOnInstalledEvent(
   }
   EventRouter* event_router = EventRouter::Get(context);
   DCHECK(event_router);
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, runtime::OnInstalled::kEventName, event_args.Pass()));
+  scoped_ptr<Event> event(new Event(events::RUNTIME_ON_INSTALLED,
+                                    runtime::OnInstalled::kEventName,
+                                    event_args.Pass()));
   event_router->DispatchEventWithLazyListener(extension_id, event.Pass());
 
   if (old_version.IsValid()) {
@@ -327,7 +329,7 @@ void RuntimeEventRouter::DispatchOnInstalledEvent(
         sm_info->SetString(kInstallReason, kInstallReasonSharedModuleUpdate);
         sm_info->SetString(kInstallPreviousVersion, old_version.GetString());
         sm_info->SetString(kInstallId, extension_id);
-        scoped_ptr<Event> sm_event(new Event(events::UNKNOWN,
+        scoped_ptr<Event> sm_event(new Event(events::RUNTIME_ON_INSTALLED,
                                              runtime::OnInstalled::kEventName,
                                              sm_event_args.Pass()));
         event_router->DispatchEventWithLazyListener((*i)->id(),
@@ -350,8 +352,9 @@ void RuntimeEventRouter::DispatchOnUpdateAvailableEvent(
   args->Append(manifest->DeepCopy());
   EventRouter* event_router = EventRouter::Get(context);
   DCHECK(event_router);
-  scoped_ptr<Event> event(new Event(
-      events::UNKNOWN, runtime::OnUpdateAvailable::kEventName, args.Pass()));
+  scoped_ptr<Event> event(new Event(events::RUNTIME_ON_UPDATE_AVAILABLE,
+                                    runtime::OnUpdateAvailable::kEventName,
+                                    args.Pass()));
   event_router->DispatchEventToExtension(extension_id, event.Pass());
 }
 
@@ -366,8 +369,8 @@ void RuntimeEventRouter::DispatchOnBrowserUpdateAvailableEvent(
   EventRouter* event_router = EventRouter::Get(context);
   DCHECK(event_router);
   scoped_ptr<Event> event(
-      new Event(events::UNKNOWN, runtime::OnBrowserUpdateAvailable::kEventName,
-                args.Pass()));
+      new Event(events::RUNTIME_ON_BROWSER_UPDATE_AVAILABLE,
+                runtime::OnBrowserUpdateAvailable::kEventName, args.Pass()));
   event_router->BroadcastEvent(event.Pass());
 }
 
@@ -381,7 +384,8 @@ void RuntimeEventRouter::DispatchOnRestartRequiredEvent(
     return;
 
   scoped_ptr<Event> event(
-      new Event(events::UNKNOWN, runtime::OnRestartRequired::kEventName,
+      new Event(events::RUNTIME_ON_RESTART_REQUIRED,
+                runtime::OnRestartRequired::kEventName,
                 core_api::runtime::OnRestartRequired::Create(reason)));
   EventRouter* event_router = EventRouter::Get(context);
   DCHECK(event_router);
diff --git a/extensions/browser/api/serial/serial_event_dispatcher.cc b/extensions/browser/api/serial/serial_event_dispatcher.cc
index d755320..cf701fe 100644
--- a/extensions/browser/api/serial/serial_event_dispatcher.cc
+++ b/extensions/browser/api/serial/serial_event_dispatcher.cc
@@ -104,7 +104,7 @@ void SerialEventDispatcher::ReceiveCallback(const ReceiveParams& params,
     receive_info.data = data;
     scoped_ptr<base::ListValue> args = serial::OnReceive::Create(receive_info);
     scoped_ptr<extensions::Event> event(
-        new extensions::Event(extensions::events::UNKNOWN,
+        new extensions::Event(extensions::events::SERIAL_ON_RECEIVE,
                               serial::OnReceive::kEventName, args.Pass()));
     PostEvent(params, event.Pass());
   }
@@ -116,7 +116,7 @@ void SerialEventDispatcher::ReceiveCallback(const ReceiveParams& params,
     scoped_ptr<base::ListValue> args =
         serial::OnReceiveError::Create(error_info);
     scoped_ptr<extensions::Event> event(
-        new extensions::Event(extensions::events::UNKNOWN,
+        new extensions::Event(extensions::events::SERIAL_ON_RECEIVE_ERROR,
                               serial::OnReceiveError::kEventName, args.Pass()));
     PostEvent(params, event.Pass());
     if (ShouldPauseOnReceiveError(error)) {
diff --git a/extensions/browser/api/sockets_tcp/tcp_socket_event_dispatcher.cc b/extensions/browser/api/sockets_tcp/tcp_socket_event_dispatcher.cc
index 3a7bcc1..91f655e 100644
--- a/extensions/browser/api/sockets_tcp/tcp_socket_event_dispatcher.cc
+++ b/extensions/browser/api/sockets_tcp/tcp_socket_event_dispatcher.cc
@@ -131,8 +131,9 @@ void TCPSocketEventDispatcher::ReadCallback(
     receive_info.data.assign(io_buffer->data(), io_buffer->data() + bytes_read);
     scoped_ptr<base::ListValue> args =
         sockets_tcp::OnReceive::Create(receive_info);
-    scoped_ptr<Event> event(new Event(
-        events::UNKNOWN, sockets_tcp::OnReceive::kEventName, args.Pass()));
+    scoped_ptr<Event> event(new Event(events::SOCKETS_TCP_ON_RECEIVE,
+                                      sockets_tcp::OnReceive::kEventName,
+                                      args.Pass()));
     PostEvent(params, event.Pass());
 
     // Post a task to delay the read until the socket is available, as
@@ -152,8 +153,9 @@ void TCPSocketEventDispatcher::ReadCallback(
     receive_error_info.result_code = bytes_read;
     scoped_ptr<base::ListValue> args =
         sockets_tcp::OnReceiveError::Create(receive_error_info);
-    scoped_ptr<Event> event(new Event(
-        events::UNKNOWN, sockets_tcp::OnReceiveError::kEventName, args.Pass()));
+    scoped_ptr<Event> event(new Event(events::SOCKETS_TCP_ON_RECEIVE_ERROR,
+                                      sockets_tcp::OnReceiveError::kEventName,
+                                      args.Pass()));
     PostEvent(params, event.Pass());
 
     // Since we got an error, the socket is now "paused" until the application
diff --git a/extensions/browser/api/sockets_tcp_server/tcp_server_socket_event_dispatcher.cc b/extensions/browser/api/sockets_tcp_server/tcp_server_socket_event_dispatcher.cc
index 5e01c44..a49f825 100644
--- a/extensions/browser/api/sockets_tcp_server/tcp_server_socket_event_dispatcher.cc
+++ b/extensions/browser/api/sockets_tcp_server/tcp_server_socket_event_dispatcher.cc
@@ -134,7 +134,7 @@ void TCPServerSocketEventDispatcher::AcceptCallback(
     accept_info.client_socket_id = client_socket_id;
     scoped_ptr<base::ListValue> args =
         sockets_tcp_server::OnAccept::Create(accept_info);
-    scoped_ptr<Event> event(new Event(events::UNKNOWN,
+    scoped_ptr<Event> event(new Event(events::SOCKETS_TCP_SERVER_ON_ACCEPT,
                                       sockets_tcp_server::OnAccept::kEventName,
                                       args.Pass()));
     PostEvent(params, event.Pass());
@@ -154,7 +154,7 @@ void TCPServerSocketEventDispatcher::AcceptCallback(
     scoped_ptr<base::ListValue> args =
         sockets_tcp_server::OnAcceptError::Create(accept_error_info);
     scoped_ptr<Event> event(
-        new Event(events::UNKNOWN,
+        new Event(events::SOCKETS_TCP_SERVER_ON_ACCEPT_ERROR,
                   sockets_tcp_server::OnAcceptError::kEventName, args.Pass()));
     PostEvent(params, event.Pass());
 
diff --git a/extensions/browser/api/sockets_udp/udp_socket_event_dispatcher.cc b/extensions/browser/api/sockets_udp/udp_socket_event_dispatcher.cc
index 87e7bc2..31b2f59 100644
--- a/extensions/browser/api/sockets_udp/udp_socket_event_dispatcher.cc
+++ b/extensions/browser/api/sockets_udp/udp_socket_event_dispatcher.cc
@@ -116,8 +116,9 @@ void UDPSocketEventDispatcher::ReceiveCallback(
     receive_info.remote_port = port;
     scoped_ptr<base::ListValue> args =
         sockets_udp::OnReceive::Create(receive_info);
-    scoped_ptr<Event> event(new Event(
-        events::UNKNOWN, sockets_udp::OnReceive::kEventName, args.Pass()));
+    scoped_ptr<Event> event(new Event(events::SOCKETS_UDP_ON_RECEIVE,
+                                      sockets_udp::OnReceive::kEventName,
+                                      args.Pass()));
     PostEvent(params, event.Pass());
 
     // Post a task to delay the read until the socket is available, as
@@ -137,8 +138,9 @@ void UDPSocketEventDispatcher::ReceiveCallback(
     receive_error_info.result_code = bytes_read;
     scoped_ptr<base::ListValue> args =
         sockets_udp::OnReceiveError::Create(receive_error_info);
-    scoped_ptr<Event> event(new Event(
-        events::UNKNOWN, sockets_udp::OnReceiveError::kEventName, args.Pass()));
+    scoped_ptr<Event> event(new Event(events::SOCKETS_UDP_ON_RECEIVE_ERROR,
+                                      sockets_udp::OnReceiveError::kEventName,
+                                      args.Pass()));
     PostEvent(params, event.Pass());
 
     // Since we got an error, the socket is now "paused" until the application
diff --git a/extensions/browser/api/storage/storage_frontend.cc b/extensions/browser/api/storage/storage_frontend.cc
index c80439f..269d483 100644
--- a/extensions/browser/api/storage/storage_frontend.cc
+++ b/extensions/browser/api/storage/storage_frontend.cc
@@ -47,7 +47,7 @@ class DefaultObserver : public SettingsObserver {
     args->Append(base::JSONReader::Read(change_json));
     args->Append(new base::StringValue(settings_namespace::ToString(
         settings_namespace)));
-    scoped_ptr<Event> event(new Event(events::UNKNOWN,
+    scoped_ptr<Event> event(new Event(events::STORAGE_ON_CHANGED,
                                       core_api::storage::OnChanged::kEventName,
                                       args.Pass()));
     EventRouter::Get(browser_context_)
diff --git a/extensions/browser/api/usb/usb_event_router.cc b/extensions/browser/api/usb/usb_event_router.cc
index 895a3b6..97fb87c 100644
--- a/extensions/browser/api/usb/usb_event_router.cc
+++ b/extensions/browser/api/usb/usb_event_router.cc
@@ -106,11 +106,13 @@ void UsbEventRouter::DispatchEvent(const std::string& event_name,
 
     scoped_ptr<Event> event;
     if (event_name == usb::OnDeviceAdded::kEventName) {
-      event.reset(new Event(events::UNKNOWN, usb::OnDeviceAdded::kEventName,
+      event.reset(new Event(events::USB_ON_DEVICE_ADDED,
+                            usb::OnDeviceAdded::kEventName,
                             usb::OnDeviceAdded::Create(device_obj)));
     } else {
       DCHECK(event_name == usb::OnDeviceRemoved::kEventName);
-      event.reset(new Event(events::UNKNOWN, usb::OnDeviceRemoved::kEventName,
+      event.reset(new Event(events::USB_ON_DEVICE_REMOVED,
+                            usb::OnDeviceRemoved::kEventName,
                             usb::OnDeviceRemoved::Create(device_obj)));
     }