Linux: Add xcb FD to glib event loop

ui/gfx/x/x11_types.cc

 // Copyright (c) 2013 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/gfx/x/x11_types.h"
 
 #include <X11/Xlib.h>
+#include <xcb/xcb.h>
+#include <X11/Xlib-xcb.h>
 
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "build/build_config.h"
 #include "ui/gfx/x/x11_switches.h"
 
 namespace gfx {
 
 XDisplay* GetXDisplay() {
   static XDisplay* display = NULL;
   if (!display)
     display = OpenNewXDisplay();
   return display;
 }
 
 XDisplay* OpenNewXDisplay() {
 #if defined(OS_CHROMEOS)
   return XOpenDisplay(NULL);
 #else
   std::string display_str = base::CommandLine::ForCurrentProcess()->
                             GetSwitchValueASCII(switches::kX11Display);
-  return XOpenDisplay(display_str.empty() ? NULL : display_str.c_str());
+  // TODO(thomasanderson): Do not upload this.  Remove once builders pass.
+  xcb_connection_t* connection =
+      xcb_connect(display_str.empty() ? NULL : display_str.c_str(), nullptr);
+  (void)connection;
+  XDisplay* display =
+      XOpenDisplay(display_str.empty() ? NULL : display_str.c_str());
+  (void)XGetXCBConnection(display);
+  return display;
 #endif
 }
 
 void PutARGBImage(XDisplay* display,
                   void* visual,
                   int depth,
                   XID pixmap,
                   void* pixmap_gc,
                   const uint8_t* data,
                   int width,
@@ skipping 126 matching lines @@
               copy_width, copy_height);
     free(orig_bitmap16);
   } else {
     LOG(FATAL) << "Sorry, we don't support your visual depth without "
                   "Xrender support (depth:" << depth
                << " bpp:" << pixmap_bpp << ")";
   }
 }
 
 }  // namespace gfx
-