Add UMA histograms for tracking empty usernames.

chrome/browser/ui/passwords/manage_passwords_ui_controller.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 "chrome/browser/ui/passwords/manage_passwords_ui_controller.h"
 
+#include "base/metrics/histogram_macros.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/browsing_data/browsing_data_helper.h"
 #include "chrome/browser/password_manager/chrome_password_manager_client.h"
 #include "chrome/browser/password_manager/password_store_factory.h"
 #include "chrome/browser/ui/browser_command_controller.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/chrome_pages.h"
 #include "chrome/browser/ui/location_bar/location_bar.h"
 #include "chrome/browser/ui/passwords/manage_passwords_icon.h"
@@ skipping 88 matching lines @@
   UpdateBubbleAndIconVisibility();
 }
 
 void ManagePasswordsUIController::OnPasswordSubmitted(
     scoped_ptr<PasswordFormManager> form_manager) {
   form_manager_ = form_manager.Pass();
   password_form_map_ = ConstifyMap(form_manager_->best_matches());
   origin_ = PendingPassword().origin;
   SetState(password_manager::ui::PENDING_PASSWORD_AND_BUBBLE_STATE);
   timer_.reset(new base::ElapsedTimer());
+  UMA_HISTOGRAM_BOOLEAN("PasswordManager.OfferSaveEmptyUsername",

[vabr (Chromium), 2015/01/29 15:40:23]

You might consider putting this in PasswordManager::AskUserOrSavePassword, so
that it works also with the infobar and on mobile.

[vasilii, 2015/01/30 12:35:41]

Done.

+                        PendingPassword().username_value.empty());
   UpdateBubbleAndIconVisibility();
 }
 
 bool ManagePasswordsUIController::OnChooseCredentials(
     ScopedVector<autofill::PasswordForm> local_credentials,
     ScopedVector<autofill::PasswordForm> federated_credentials,
     base::Callback<void(const password_manager::CredentialInfo&)> callback){
   DCHECK(!local_credentials.empty() || !federated_credentials.empty());
   form_manager_.reset();
   // TODO(melandory): fix the crash when |local_credentials| is empty.
@@ skipping 231 matching lines @@
 bool ManagePasswordsUIController::PasswordPendingUserDecision() const {
   return password_manager::ui::IsPendingState(state_);
 }
 
 void ManagePasswordsUIController::WebContentsDestroyed() {
   password_manager::PasswordStore* password_store =
       GetPasswordStore(web_contents());
   if (password_store)
     password_store->RemoveObserver(this);
 }