Condition the use of ChromeBrowserMainExtraPartsViewsLinux to !use_ozone

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 97baa3b5f8799f33c931caa394f94fbd26813f7f..76a5f013c2cd7e2c7776aa94cce48005f9b9fdbe 100644
--- a/chrome/browser/ui/BUILD.gn
+++ b/chrome/browser/ui/BUILD.gn
@@ -1516,8 +1516,6 @@ split_static_library("ui") {
       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",
@@ -1537,6 +1535,19 @@ split_static_library("ui") {
         "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 this files in case Gtk is available with its Wayland

[fwang, 2016/11/01 17:47:20]

*these* files

+      # backend. An extra GN vaiable to control it would be safer.

[fwang, 2016/11/01 17:47:20]

*variable*

+      if (!use_ozone) {
+        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 += [