x11: Use scoped_ptr<> for X11 objects where it makes sense.

content/common/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//content/common/common.gni")
 import("//third_party/mojo/src/mojo/public/tools/bindings/mojom.gni")
 
 if (is_chromeos && current_cpu != "arm") {
@@ skipping 265 matching lines @@
     }
   } else {
     sources -= [ "font_list_pango.cc" ]
   }
 
   if (use_x11) {
     include_dirs += [ "//third_party/khronos" ]
     configs += [ "//build/config/linux:xcomposite" ]
 
     if (current_cpu != "arm" || !is_chromeos) {
-      sources += [
-        "gpu/x_util.cc",
-        "gpu/x_util.h",
-      ]
+      sources += [ "gpu/x_util.h" ]
     }
   }
 
   if (enable_plugins) {
     deps += [ "//ppapi/shared_impl" ]
   } else {
     sources -= [
       "pepper_file_util.cc",
       "pepper_file_util.h",
       "pepper_messages.h",
@@ skipping 173 matching lines @@
     "presentation/presentation_service.mojom",
     "presentation/presentation_session.mojom",
     "render_frame_setup.mojom",
   ]
 
   deps = [
     "//content/public/common:mojo_bindings",
     "//third_party/mojo/src/mojo/public/interfaces/application:application",
   ]
 }