GN: Add -Wl,-z defs on linux and fix errors

ui/aura/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/ui.gni")
 
 component("aura") {
   sources = [
     "client/aura_constants.cc",
     "client/aura_constants.h",
@@ skipping 92 matching lines @@
     "//ui/events/platform",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 
   if (use_x11) {
     configs += [
       "//build/config/linux:x11",
       "//build/config/linux:xrandr",
     ]
-    deps += [ "//ui/events/platform/x11" ]
+    deps += [
+      "//ui/events:events_base",
+      "//ui/events/devices",

[Nico, 2015/01/15 23:35:07]

Are both of these only needed if use_x11? (not sure if there are non-x11 linux
builds on gn yet)

[jamesr, 2015/01/16 02:00:45]

The references are in window_tree_host_x11.cc so I believe the dependency is
X11-only

+      "//ui/events/platform/x11",
+      "//ui/gfx/x",
+    ]
   } else {
     sources -= [
       "window_tree_host_x11.cc",
       "window_tree_host_x11.h",
     ]
   }
 
   if (is_win) {
     sources -= [ "input_state_lookup.cc" ]
 
@@ skipping 158 matching lines @@
     "//ui/events:gesture_detection",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/gl",
   ]
 
   if (is_linux) {
     deps += [ "//third_party/mesa" ]
   }
 }