X11 and Ozone: cleanup //extensions for use_x11 && use_ozone build.

Sets touch device list from cmd line only for non-ozone/X11 for now.

-----

PS: Please note that this is a temp solution that will help to choose
between ozone and non-ozone X11 build. The switch that will be used
to choose the path is --enable-features=UseOzonePlatform. Once
non-Ozone X11 path is removed (hopefully by Q1 2021 depending on how
th finch trial goes), the wrapper will be removed.

Please also note that it's impossible to build use_x11 && use_ozone
without some hacks in PlatformCursor code. The changes to that are
on their way to upstream.

----

Bug: 1085700
Change-Id: Iffc4c78d2911d13ace9cc5661c49b69243a6b63c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2315886Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Commit-Queue: Maksim Sisov (GMT+3) <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#791340}

extensions/shell/browser/shell_browser_main_parts.cc

@@ -77,6 +77,7 @@
 #endif
 
 #if defined(USE_AURA) && defined(USE_X11)
+#include "ui/base/ui_base_features.h"
 #include "ui/events/devices/x11/touch_factory_x11.h"  // nogncheck
 #endif
 
@@ -112,7 +113,8 @@ ShellBrowserMainParts::~ShellBrowserMainParts() {
 
 void ShellBrowserMainParts::PreMainMessageLoopStart() {
 #if defined(USE_AURA) && defined(USE_X11)
-  ui::TouchFactory::SetTouchDeviceListFromCommandLine();
+  if (!features::IsUsingOzonePlatform())
+    ui::TouchFactory::SetTouchDeviceListFromCommandLine();
 #endif
 }