Revert of Add SafeBrowsingNavigationObserver to listen to navigation events

chrome/browser/BUILD.gn

 # 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 1938 matching lines @@
       "loader/data_reduction_proxy_resource_throttle_android.cc",
       "loader/data_reduction_proxy_resource_throttle_android.h",
       "safe_browsing/permission_reporter.cc",
       "safe_browsing/permission_reporter.h",
       "safe_browsing/ping_manager.cc",
       "safe_browsing/ping_manager.h",
       "safe_browsing/protocol_manager_helper.cc",
       "safe_browsing/protocol_manager_helper.h",
       "safe_browsing/safe_browsing_blocking_page.cc",
       "safe_browsing/safe_browsing_blocking_page.h",
-      "safe_browsing/safe_browsing_navigation_observer.cc",
-      "safe_browsing/safe_browsing_navigation_observer.h",
-      "safe_browsing/safe_browsing_navigation_observer_manager.cc",
-      "safe_browsing/safe_browsing_navigation_observer_manager.h",
       "safe_browsing/safe_browsing_service.cc",
       "safe_browsing/safe_browsing_service.h",
       "safe_browsing/services_delegate.h",
       "safe_browsing/test_safe_browsing_service.cc",
       "safe_browsing/test_safe_browsing_service.h",
       "safe_browsing/threat_details.cc",
       "safe_browsing/threat_details.h",
       "safe_browsing/threat_details_cache.cc",
       "safe_browsing/threat_details_cache.h",
       "safe_browsing/threat_details_history.cc",
@@ skipping 2399 matching lines @@
   # linking all of the test support.
   static_library("pepper_cdm_test_constants") {
     testonly = true
     visibility = [ "//chrome/*" ]
     sources = [
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }