Set the WM_CLASS property of X11 windows in Linux Aura build.

ui/views/widget/desktop_aura/desktop_root_window_host_x11.cc

 // Copyright (c) 2012 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.
 
 #include "ui/views/widget/desktop_aura/desktop_root_window_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 846 matching lines @@
     // SetWMSpecState) has no effect here since the window has not yet been
     // mapped. So we manually change the state.
     XChangeProperty (xdisplay_,
                      xwindow_,
                      atom_cache_.GetAtom("_NET_WM_STATE"),
                      XA_ATOM,
                      32,
                      PropModeAppend,
                      reinterpret_cast<unsigned char*>(&atom), 1);
   }
+
+  if (!params.wm_class_name.empty() || !params.wm_class_class.empty()) {
+    ui::SetWindowClassHint(
+        xdisplay_, xwindow_, params.wm_class_name, params.wm_class_class);
+  }
 }
 
 // TODO(erg): This method should basically be everything I need form
 // RootWindowHostX11::RootWindowHostX11().
 aura::RootWindow* DesktopRootWindowHostX11::InitRootWindow(
     const Widget::InitParams& params) {
   bounds_ = params.bounds;
 
   aura::RootWindow::CreateParams rw_params(bounds_);
   rw_params.host = this;
@@ skipping 459 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme();
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeTheme::instance();
 }
 
 }  // namespace views