Condition the use of ChromeBrowserMainExtraPartsViewsLinux to !use_ozone

chrome/browser/ui/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/chromecast_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 1502 matching lines @@
 
     if (is_chromeos) {
       sources += [
         "views/apps/app_info_dialog/arc_app_info_links_panel.cc",
         "views/apps/app_info_dialog/arc_app_info_links_panel.h",
       ]
     } else if (!is_mac || mac_views_browser) {
       sources += [
         "external_protocol_dialog_delegate.cc",
         "external_protocol_dialog_delegate.h",
-        "views/chrome_browser_main_extra_parts_views_linux.cc",
-        "views/chrome_browser_main_extra_parts_views_linux.h",
         "views/external_protocol_dialog.cc",
         "views/external_protocol_dialog.h",
         "views/frame/opaque_browser_frame_view.cc",
         "views/frame/opaque_browser_frame_view.h",
         "views/frame/opaque_browser_frame_view_layout.cc",
         "views/frame/opaque_browser_frame_view_layout.h",
         "views/frame/opaque_browser_frame_view_layout_delegate.h",
         "views/frame/opaque_browser_frame_view_linux.cc",
         "views/frame/opaque_browser_frame_view_linux.h",
         "views/frame/opaque_browser_frame_view_platform_specific.cc",
         "views/frame/opaque_browser_frame_view_platform_specific.h",
         "views/profiles/profile_chooser_view.cc",
         "views/profiles/profile_chooser_view.h",
         "views/screen_capture_notification_ui_views.cc",
         "views/sync/one_click_signin_dialog_view.cc",
         "views/sync/one_click_signin_dialog_view.h",
         "views/sync/profile_signin_confirmation_dialog_views.cc",
         "views/sync/profile_signin_confirmation_dialog_views.h",
       ]
     }
+
+    # These files do Gtk+-based theming, but Gtk+ is not available on
+    # Ozone builds, or on common environments where Ozone will be used.
+    #
+    # TODO(tonikitoo): It seems sensible to make it possible to opt-in
+    # the use of these files in case Gtk is available with its Wayland.
+    if (use_aura && !use_ozone && is_desktop_linux) {
+      sources += [
+        "views/chrome_browser_main_extra_parts_views_linux.cc",
+        "views/chrome_browser_main_extra_parts_views_linux.h",
+      ]
+    }
     if (enable_extensions && (!is_mac || mac_views_browser)) {
       sources += [
         "views/extensions/bookmark_app_confirmation_view.cc",
         "views/extensions/bookmark_app_confirmation_view.h",
         "views/extensions/browser_action_drag_data.cc",
         "views/extensions/browser_action_drag_data.h",
         "views/extensions/extension_action_platform_delegate_views.cc",
         "views/extensions/extension_action_platform_delegate_views.h",
         "views/extensions/extension_dialog.cc",
         "views/extensions/extension_dialog.h",
@@ skipping 1877 matching lines @@
       "test/test_confirm_bubble_model.cc",
       "test/test_confirm_bubble_model.h",
     ]
     deps += [ "//chrome/test:test_support_ui" ]
   }
 
   if (enable_extensions) {
     deps += [ "//extensions/browser" ]
   }
 }