Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/downloads/downloads_api.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/api/downloads/downloads_api.h"
 
 #include <set>
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 1844 matching lines @@
     bool include_incognito,
     const Event::WillDispatchCallback& will_dispatch_callback,
     base::Value* arg) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (!EventRouter::Get(profile_))
     return;
   scoped_ptr<base::ListValue> args(new base::ListValue());
   args->Append(arg);
   std::string json_args;
   base::JSONWriter::Write(*args, &json_args);
-  scoped_ptr<Event> event(new Event(event_name, args.Pass()));
+  scoped_ptr<Event> event(new Event(events::UNKNOWN, event_name, args.Pass()));
   // The downloads system wants to share on-record events with off-record
   // extension renderers even in incognito_split_mode because that's how
   // chrome://downloads works. The "restrict_to_profile" mechanism does not
   // anticipate this, so it does not automatically prevent sharing off-record
   // events with on-record extension renderers.
   event->restrict_to_browser_context =
       (include_incognito && !profile_->IsOffTheRecord()) ? NULL : profile_;
   event->will_dispatch_callback = will_dispatch_callback;
   EventRouter::Get(profile_)->BroadcastEvent(event.Pass());
   DownloadsNotificationSource notification_source;
@@ skipping 25 matching lines @@
     return;
   base::Time now(base::Time::Now());
   int delta = now.ToTimeT() - last_checked_removal_.ToTimeT();
   if (delta <= kFileExistenceRateLimitSeconds)
     return;
   last_checked_removal_ = now;
   manager->CheckForHistoryFilesRemoval();
 }
 
 }  // namespace extensions