Provide a default role for "bubble" windows.

ui/views/widget/desktop_aura/desktop_window_tree_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_window_tree_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 103 matching lines @@
   "XdndFinished",
   "XdndLeave",
   "XdndPosition",
   "XdndProxy",  // Proxy windows?
   "XdndSelection",
   "XdndStatus",
   "XdndTypeList",
   NULL
 };
 
+const char kX11WindowRolePopup[] = "popup";
+const char kX11WindowRoleBubble[] = "bubble";
+
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopWindowTreeHostX11, public:
 
 DesktopWindowTreeHostX11::DesktopWindowTreeHostX11(
     internal::NativeWidgetDelegate* native_widget_delegate,
     DesktopNativeWidgetAura* desktop_native_widget_aura)
     : xdisplay_(gfx::GetXDisplay()),
       xwindow_(0),
@@ skipping 1044 matching lines @@
     ui::SetAtomArrayProperty(xwindow_,
                              "_NET_WM_STATE",
                              "ATOM",
                              state_atom_list);
   }
 
   if (!params.wm_class_name.empty() || !params.wm_class_class.empty()) {
     ui::SetWindowClassHint(
         xdisplay_, xwindow_, params.wm_class_name, params.wm_class_class);
   }
-  if (!params.wm_role_name.empty() ||
-      params.type == Widget::InitParams::TYPE_POPUP) {
-    const char kX11WindowRolePopup[] = "popup";
-    ui::SetWindowRole(xdisplay_, xwindow_, params.wm_role_name.empty() ?
-                      std::string(kX11WindowRolePopup) : params.wm_role_name);
+
+  const char* wm_role_name = NULL;
+  // If the widget isn't overriding the role, provide a default value for popup
+  // and bubble types.
+  if (!params.wm_role_name.empty()) {
+    wm_role_name = params.wm_role_name.c_str();
+  } else {
+    switch (params.type) {
+      case Widget::InitParams::TYPE_POPUP:
+        wm_role_name = kX11WindowRolePopup;
+        break;
+      case Widget::InitParams::TYPE_BUBBLE:
+        wm_role_name = kX11WindowRoleBubble;
+        break;
+      default:
+        break;
+    }
   }
+  if (wm_role_name)
+    ui::SetWindowRole(xdisplay_, xwindow_, std::string(wm_role_name));
 
   if (params.remove_standard_frame) {
     // Setting _GTK_HIDE_TITLEBAR_WHEN_MAXIMIZED tells gnome-shell to not force
     // fullscreen on the window when it matches the desktop size.
     ui::SetHideTitlebarWhenMaximizedProperty(xwindow_,
                                              ui::HIDE_TITLEBAR_WHEN_MAXIMIZED);
   }
 
   // If we have a parent, record the parent/child relationship. We use this
   // data during destruction to make sure that when we try to close a parent
@@ skipping 739 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme(window);
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeTheme::instance();
 }
 
 }  // namespace views