gtk: Allow building both the X11 and Gtk message-pumps for gtk.

ui/views/widget/desktop_aura/x11_desktop_handler.cc

Index: ui/views/widget/desktop_aura/x11_desktop_handler.cc
diff --git a/ui/views/widget/desktop_aura/x11_desktop_handler.cc b/ui/views/widget/desktop_aura/x11_desktop_handler.cc
index 4c38fa7e5245fd166bbd65a24495827cdf466ba0..6b2d3b58a082302a490d8105afae1ef2544f39ff 100644
--- a/ui/views/widget/desktop_aura/x11_desktop_handler.cc
+++ b/ui/views/widget/desktop_aura/x11_desktop_handler.cc
@@ -38,11 +38,11 @@ X11DesktopHandler* X11DesktopHandler::get() {
 }
 
 X11DesktopHandler::X11DesktopHandler()
-    : xdisplay_(base::MessagePumpAuraX11::GetDefaultXDisplay()),
+    : xdisplay_(base::MessagePumpX11::GetDefaultXDisplay()),
       x_root_window_(DefaultRootWindow(xdisplay_)),
       current_window_(None),
       atom_cache_(xdisplay_, kAtomsToCache) {
-  base::MessagePumpAuraX11::Current()->AddDispatcherForRootWindow(this);
+  base::MessagePumpX11::Current()->AddDispatcherForRootWindow(this);
   aura::Env::GetInstance()->AddObserver(this);
 
   XWindowAttributes attr;
@@ -54,11 +54,11 @@ X11DesktopHandler::X11DesktopHandler()
 
 X11DesktopHandler::~X11DesktopHandler() {
   aura::Env::GetInstance()->RemoveObserver(this);
-  base::MessagePumpAuraX11::Current()->RemoveDispatcherForRootWindow(this);
+  base::MessagePumpX11::Current()->RemoveDispatcherForRootWindow(this);
 }
 
 void X11DesktopHandler::ActivateWindow(::Window window) {
-  DCHECK_EQ(base::MessagePumpAuraX11::GetDefaultXDisplay(), xdisplay_);
+  DCHECK_EQ(base::MessagePumpX11::GetDefaultXDisplay(), xdisplay_);
 
   XEvent xclient;
   memset(&xclient, 0, sizeof(xclient));