Set up the infrastructure for Extension event metrics.

extensions/shell/browser/shell_extensions_browser_client.cc

 // Copyright 2014 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 "extensions/shell/browser/shell_extensions_browser_client.h"
 
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_frame_host.h"
 #include "extensions/browser/api/extensions_api_client.h"
@@ skipping 197 matching lines @@
     BrowserThread::PostTask(
         BrowserThread::UI,
         FROM_HERE,
         base::Bind(&ShellExtensionsBrowserClient::BroadcastEventToRenderers,
                    base::Unretained(this),
                    event_name,
                    base::Passed(&args)));
     return;
   }
 
-  scoped_ptr<Event> event(new Event(event_name, args.Pass()));
+  scoped_ptr<Event> event(new Event(events::UNKNOWN, event_name, args.Pass()));
   EventRouter::Get(browser_context_)->BroadcastEvent(event.Pass());
 }
 
 net::NetLog* ShellExtensionsBrowserClient::GetNetLog() {
   return NULL;
 }
 
 ExtensionCache* ShellExtensionsBrowserClient::GetExtensionCache() {
   return extension_cache_.get();
 }
@@ skipping 12 matching lines @@
   api_client_.reset(api_client);
 }
 
 ExtensionWebContentsObserver*
 ShellExtensionsBrowserClient::GetExtensionWebContentsObserver(
     content::WebContents* web_contents) {
   return ShellExtensionWebContentsObserver::FromWebContents(web_contents);
 }
 
 }  // namespace extensions