Move ui::GetAtom to gfx::GetAtom

ui/aura/window_tree_host_x11.cc

Index: ui/aura/window_tree_host_x11.cc
diff --git a/ui/aura/window_tree_host_x11.cc b/ui/aura/window_tree_host_x11.cc
index f59d99ecee569cdff01cbcc1ad6a9fb2c619c73f..0635b7a65ff21e4b22f58649ced937e831269c81 100644
--- a/ui/aura/window_tree_host_x11.cc
+++ b/ui/aura/window_tree_host_x11.cc
@@ -51,6 +51,7 @@
 #include "ui/events/platform/platform_event_observer.h"
 #include "ui/events/platform/platform_event_source.h"
 #include "ui/events/platform/x11/x11_event_source.h"
+#include "ui/gfx/x/x11_atom_cache.h"
 
 using std::max;
 using std::min;
@@ -145,8 +146,8 @@ WindowTreeHostX11::WindowTreeHostX11(const gfx::Rect& bounds)
   // should listen for activation events and anything else that GTK+ listens
   // for, and do something useful.
   ::Atom protocols[2];
-  protocols[0] = ui::GetAtom("WM_DELETE_WINDOW");
-  protocols[1] = ui::GetAtom("_NET_WM_PING");
+  protocols[0] = gfx::GetAtom("WM_DELETE_WINDOW");
+  protocols[1] = gfx::GetAtom("_NET_WM_PING");
   XSetWMProtocols(xdisplay_, xwindow_, protocols, 2);
 
   // We need a WM_CLIENT_MACHINE and WM_LOCALE_NAME value so we integrate with
@@ -160,7 +161,7 @@ WindowTreeHostX11::WindowTreeHostX11(const gfx::Rect& bounds)
   static_assert(sizeof(long) >= sizeof(pid_t),
                 "pid_t should not be larger than long");
   long pid = getpid();
-  XChangeProperty(xdisplay_, xwindow_, ui::GetAtom("_NET_WM_PID"), XA_CARDINAL,
+  XChangeProperty(xdisplay_, xwindow_, gfx::GetAtom("_NET_WM_PID"), XA_CARDINAL,
                   32, PropModeReplace, reinterpret_cast<unsigned char*>(&pid),
                   1);
 
@@ -307,10 +308,10 @@ uint32_t WindowTreeHostX11::DispatchEvent(const ui::PlatformEvent& event) {
       break;
     case ClientMessage: {
       Atom message_type = static_cast<Atom>(xev->xclient.data.l[0]);
-      if (message_type == ui::GetAtom("WM_DELETE_WINDOW")) {
+      if (message_type == gfx::GetAtom("WM_DELETE_WINDOW")) {
         // We have received a close message from the window manager.
         OnHostCloseRequested();
-      } else if (message_type == ui::GetAtom("_NET_WM_PING")) {
+      } else if (message_type == gfx::GetAtom("_NET_WM_PING")) {
         XEvent reply_event = *xev;
         reply_event.xclient.window = x_root_window_;