Rename DesktopEngagement* to DesktopSessionDuration*.

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 2434 matching lines @@
       "sessions/session_service_utils.h",
       "sessions/tab_loader.cc",
       "sessions/tab_loader.h",
       "sessions/tab_loader_delegate.cc",
       "sessions/tab_loader_delegate.h",
     ]
   }
 
   if (!is_android && !is_chromeos) {
     sources += [
-      "metrics/desktop_engagement/audible_contents_tracker.cc",
-      "metrics/desktop_engagement/audible_contents_tracker.h",
-      "metrics/desktop_engagement/chrome_visibility_observer.cc",
-      "metrics/desktop_engagement/chrome_visibility_observer.h",
-      "metrics/desktop_engagement/desktop_engagement_observer.cc",
-      "metrics/desktop_engagement/desktop_engagement_observer.h",
-      "metrics/desktop_engagement/desktop_engagement_service.cc",
-      "metrics/desktop_engagement/desktop_engagement_service.h",
+      "metrics/desktop_session_duration/audible_contents_tracker.cc",
+      "metrics/desktop_session_duration/audible_contents_tracker.h",
+      "metrics/desktop_session_duration/chrome_visibility_observer.cc",
+      "metrics/desktop_session_duration/chrome_visibility_observer.h",
+      "metrics/desktop_session_duration/desktop_session_duration_observer.cc",
+      "metrics/desktop_session_duration/desktop_session_duration_observer.h",
+      "metrics/desktop_session_duration/desktop_session_duration_tracker.cc",
+      "metrics/desktop_session_duration/desktop_session_duration_tracker.h",
       "net/disk_cache_dir_policy_handler.cc",
       "net/disk_cache_dir_policy_handler.h",
       "platform_util.cc",
       "policy/cloud/user_policy_signin_service.cc",
       "policy/cloud/user_policy_signin_service.h",
       "profiles/avatar_menu_actions_desktop.cc",
       "profiles/avatar_menu_actions_desktop.h",
       "profiles/avatar_menu_desktop.cc",
       "profiles/avatar_menu_observer.h",
       "profiles/profile_list_desktop.cc",
@@ skipping 1766 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",
     ]
   }
 }