Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/audio_modem/audio_modem_api.cc

 // Copyright 2015 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 <map>
 #include <string>
 #include <vector>
 
 #include "base/base64.h"
 #include "base/bind.h"
@@ skipping 226 matching lines @@
     }
   }
 
   // Send events to the appropriate app(s).
   for (const auto& app_entry : tokens_by_app) {
     const std::string& app_id = app_entry.first;
     const auto& tokens = app_entry.second;
     if (app_id.empty())
       continue;
 
-    EventRouter::Get(browser_context_)->DispatchEventToExtension(
-      app_id,
-      make_scoped_ptr(new Event(OnReceived::kEventName,
-                                OnReceived::Create(tokens))));
+    EventRouter::Get(browser_context_)
+        ->DispatchEventToExtension(
+            app_id,
+            make_scoped_ptr(new Event(events::UNKNOWN, OnReceived::kEventName,
+                                      OnReceived::Create(tokens))));
   }
 }
 
 
 // Functions outside the API scope.
 
 template <>
 void
 BrowserContextKeyedAPIFactory<AudioModemAPI>::DeclareFactoryDependencies() {
   DependsOn(ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
@@ skipping 78 matching lines @@
 ExtensionFunction::ResponseAction AudioModemStopReceiveFunction::Run() {
   scoped_ptr<StopReceive::Params> params(StopReceive::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
 
   Status status = AudioModemAPI::GetFactoryInstance()->Get(browser_context())
       ->StopReceive(extension_id(), AudioTypeForBand(params->band));
   return RespondNow(ArgumentList(StopReceive::Results::Create(status)));
 }
 
 }  // namespace extensions