Remove obsolete app_list Linux code.

chrome/browser/ui/BUILD.gn

Index: chrome/browser/ui/BUILD.gn
diff --git a/chrome/browser/ui/BUILD.gn b/chrome/browser/ui/BUILD.gn
index 2585910053bec76dfa0888308d273b57dbab79dc..d3334d29f3b5004be5aefadca32a130127abe688 100644
--- a/chrome/browser/ui/BUILD.gn
+++ b/chrome/browser/ui/BUILD.gn
@@ -3143,8 +3143,6 @@ split_static_library("ui") {
       "app_list/app_list_controller_delegate_impl.h",
       "app_list/app_list_model_builder.cc",
       "app_list/app_list_model_builder.h",
-      "app_list/app_list_positioner.cc",
-      "app_list/app_list_positioner.h",
       "app_list/app_list_service.cc",
       "app_list/app_list_service.h",
       "app_list/app_list_service_impl.cc",
@@ -3165,8 +3163,6 @@ split_static_library("ui") {
       "app_list/extension_app_model_builder.h",
       "app_list/extension_uninstaller.cc",
       "app_list/extension_uninstaller.h",
-      "app_list/fast_show_pickler.cc",
-      "app_list/fast_show_pickler.h",
       "app_list/google_now_extension.cc",
       "app_list/google_now_extension.h",
       "app_list/launcher_page_event_dispatcher.cc",
@@ -3277,24 +3273,6 @@ split_static_library("ui") {
         "views/arc_app_dialog_view.cc",
       ]
     }
-    if (is_desktop_linux) {
-      sources += [
-        "views/app_list/linux/app_list_linux.cc",
-        "views/app_list/linux/app_list_linux.h",
-        "views/app_list/linux/app_list_service_linux.cc",
-        "views/app_list/linux/app_list_service_linux.h",
-      ]
-    }
-    if (!is_mac && !use_ash) {
-      sources += [
-        "app_list/app_list_controller_delegate_views.cc",
-        "app_list/app_list_controller_delegate_views.h",
-        "app_list/app_list_service_views.cc",
-        "app_list/app_list_service_views.h",
-        "app_list/app_list_shower_views.cc",
-        "app_list/app_list_shower_views.h",
-      ]
-    }
     deps += [ "//ui/app_list" ]
   } else {
     sources += [