Deprecate Once-Per-Origin Navigation histograms

ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.h

Index: ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.h
diff --git a/ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.h b/ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.h
deleted file mode 100644
index a4507d9807ad3b763b5684463b7bcac91514c16e..0000000000000000000000000000000000000000
--- a/ios/chrome/browser/metrics/ios_chrome_origins_seen_service_factory.h
+++ /dev/null
@@ -1,51 +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.
-
-#ifndef IOS_CHROME_BROWSER_METRICS_IOS_CHROME_ORIGINS_SEEN_SERVICE_FACTORY_H_
-#define IOS_CHROME_BROWSER_METRICS_IOS_CHROME_ORIGINS_SEEN_SERVICE_FACTORY_H_
-
-#include <memory>
-
-#include "base/macros.h"
-#include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
-
-namespace base {
-template <typename T>
-struct DefaultSingletonTraits;
-}
-
-namespace ios {
-class ChromeBrowserState;
-}
-
-namespace navigation_metrics {
-class OriginsSeenService;
-}
-
-// Singleton that owns all OriginsSeenService and associates them with
-// ios::ChromeBrowserState.
-class IOSChromeOriginsSeenServiceFactory
-    : public BrowserStateKeyedServiceFactory {
- public:
-  static navigation_metrics::OriginsSeenService* GetForBrowserState(
-      ios::ChromeBrowserState* browser_state);
-  static IOSChromeOriginsSeenServiceFactory* GetInstance();
-
- private:
-  friend struct base::DefaultSingletonTraits<
-      IOSChromeOriginsSeenServiceFactory>;
-
-  IOSChromeOriginsSeenServiceFactory();
-  ~IOSChromeOriginsSeenServiceFactory() override;
-
-  // BrowserStateKeyedServiceFactory implementation.
-  std::unique_ptr<KeyedService> BuildServiceInstanceFor(
-      web::BrowserState* context) const override;
-  web::BrowserState* GetBrowserStateToUse(
-      web::BrowserState* context) const override;
-
-  DISALLOW_COPY_AND_ASSIGN(IOSChromeOriginsSeenServiceFactory);
-};
-
-#endif  // IOS_CHROME_BROWSER_METRICS_IOS_CHROME_ORIGINS_SEEN_SERVICE_FACTORY_H_