x11: Move X event handling out of the message-pump.

ash/shell/content_client/shell_browser_main_parts.h

Index: ash/shell/content_client/shell_browser_main_parts.h
diff --git a/ash/shell/content_client/shell_browser_main_parts.h b/ash/shell/content_client/shell_browser_main_parts.h
index 0e07cbf24bc6850985f5f60a6916009b9bcee68d..b765f07aa90a51f7ba9106f4e3448319ba2016bf 100644
--- a/ash/shell/content_client/shell_browser_main_parts.h
+++ b/ash/shell/content_client/shell_browser_main_parts.h
@@ -22,6 +22,10 @@ namespace net {
 class NetLog;
 }
 
+namespace ui {
+class PlatformEventSource;
+}
+
 namespace wm {
 class WMState;
 }
@@ -56,6 +60,7 @@ class ShellBrowserMainParts : public content::BrowserMainParts {
   scoped_ptr<ash::shell::WindowWatcher> window_watcher_;
   ShellDelegateImpl* delegate_;  // owned by Shell
   scoped_ptr<wm::WMState> wm_state_;
+  scoped_ptr<ui::PlatformEventSource> event_source_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellBrowserMainParts);
 };