Chrome OS: avoid suspending on lid close when casting is active.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 532da3e7fd56a71f1e7faec89a07a28f571bab13..c15fe1ae058a9a35ac6dc66d9cdf8bd8110325bb 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -374,6 +374,13 @@ void Shell::OnLockStateChanged(bool locked) {
 #endif
 }
 
+void Shell::OnScreenSharingStateChanged(bool started) {
+#if defined(OS_CHROMEOS) && defined(USE_X11)
+  if (output_configurator_)
+    output_configurator_->OnScreenSharingStateChanged(started);
+#endif
+}
+
 void Shell::CreateShelf() {
   RootWindowControllerList controllers = GetAllRootWindowControllers();
   for (RootWindowControllerList::iterator iter = controllers.begin();