[jumbo] X11/gfx: Need to say ::Display or it's ambiguous.

There are several classes/types named Display so to get
the X11 one, you have to specify it with ::Display (gfx::Display
is a common alternative when you're inside the gfx namespace).

TBR=hubbe@google.com

Bug: 822068
Change-Id: I402b7ad2d37a82d3091577733f3f06e673c29c7e
Reviewed-on: https://chromium-review.googlesource.com/994212
Commit-Queue: Daniel Bratell <bratell@opera.com>
Reviewed-by: Fredrik Hubinette <hubbe@chromium.org>
Reviewed-by: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#547916}

ui/views/widget/desktop_aura/desktop_screen_x11.cc

@@ -330,7 +330,7 @@ std::vector<display::Display> DesktopScreenX11::BuildDisplaysFromXRandRInfo() {
   if (xrandr_version_ >= 105) {
     void* xrandr_lib = dlopen(NULL, RTLD_NOW);
     if (xrandr_lib) {
-      typedef XRRMonitorInfo* (*XRRGetMonitors_type)(Display*, Window, bool,
+      typedef XRRMonitorInfo* (*XRRGetMonitors_type)(::Display*, Window, bool,
                                                      int*);
       typedef void (*XRRFreeMonitors_type)(XRRMonitorInfo*);
       XRRGetMonitors_type XRRGetMonitors_ptr =