Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/identity/web_auth_flow.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/identity/web_auth_flow.h"
 
 #include "base/base64.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
@@ skipping 71 matching lines @@
   // identityPrivate.onWebFlowRequest(app_window_key, provider_url_, mode_)
   scoped_ptr<base::ListValue> args(new base::ListValue());
   args->AppendString(app_window_key_);
   args->AppendString(provider_url_.spec());
   if (mode_ == WebAuthFlow::INTERACTIVE)
     args->AppendString("interactive");
   else
     args->AppendString("silent");
 
   scoped_ptr<Event> event(
-      new Event(identity_private::OnWebFlowRequest::kEventName, args.Pass()));
+      new Event(events::UNKNOWN, identity_private::OnWebFlowRequest::kEventName,
+                args.Pass()));
   event->restrict_to_browser_context = profile_;
   ExtensionSystem* system = ExtensionSystem::Get(profile_);
 
   extensions::ComponentLoader* component_loader =
       system->extension_service()->component_loader();
   if (!component_loader->Exists(extension_misc::kIdentityApiUiAppId)) {
     component_loader->Add(
         IDR_IDENTITY_API_SCOPE_APPROVAL_MANIFEST,
         base::FilePath(FILE_PATH_LITERAL("identity_scope_approval_dialog")));
   }
@@ skipping 134 matching lines @@
 }
 
 void WebAuthFlow::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   if (delegate_ && details.http_status_code >= 400)
     delegate_->OnAuthFlowFailure(LOAD_FAILED);
 }
 
 }  // namespace extensions