Deprecate Once-Per-Origin Navigation histograms

ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.cc

Index: ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.cc
diff --git a/ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.cc b/ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.cc
deleted file mode 100644
index 4e9636a35798d7045ba9ad4c9118f31a90a8cb5f..0000000000000000000000000000000000000000
--- a/ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.cc
+++ /dev/null
@@ -1,44 +0,0 @@
-// Copyright 2016 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 "ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.h"
-
-#include "base/memory/ptr_util.h"
-#include "base/memory/singleton.h"
-#include "components/keyed_service/ios/browser_state_dependency_manager.h"
-#include "components/navigation_metrics/origins_seen_service.h"
-#include "ios/chrome/browser/browser_state/browser_state_otr_helper.h"
-#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
-
-// static
-navigation_metrics::OriginsSeenService*
-IOSChromeOriginsSeenServiceFactory::GetForBrowserState(
-    ios::ChromeBrowserState* browser_state) {
-  return static_cast<navigation_metrics::OriginsSeenService*>(
-      GetInstance()->GetServiceForBrowserState(browser_state, true));
-}
-
-// static
-IOSChromeOriginsSeenServiceFactory*
-IOSChromeOriginsSeenServiceFactory::GetInstance() {
-  return base::Singleton<IOSChromeOriginsSeenServiceFactory>::get();
-}
-
-IOSChromeOriginsSeenServiceFactory::IOSChromeOriginsSeenServiceFactory()
-    : BrowserStateKeyedServiceFactory(
-          "OriginsSeenService",
-          BrowserStateDependencyManager::GetInstance()) {}
-
-IOSChromeOriginsSeenServiceFactory::~IOSChromeOriginsSeenServiceFactory() {}
-
-std::unique_ptr<KeyedService>
-IOSChromeOriginsSeenServiceFactory::BuildServiceInstanceFor(
-    web::BrowserState* context) const {
-  return base::MakeUnique<navigation_metrics::OriginsSeenService>();
-}
-
-web::BrowserState* IOSChromeOriginsSeenServiceFactory::GetBrowserStateToUse(
-    web::BrowserState* context) const {
-  return GetBrowserStateOwnInstanceInIncognito(context);
-}