Remove DisplayState from the public interface for DisplayConfigurator

ash/wm/power_button_controller.cc

Index: ash/wm/power_button_controller.cc
diff --git a/ash/wm/power_button_controller.cc b/ash/wm/power_button_controller.cc
index 5d70803b134f82e10f7fd829e49349aaedc48a6b..5899b8a472675b02d1666dccbfb391b118a7f9a7 100644
--- a/ash/wm/power_button_controller.cc
+++ b/ash/wm/power_button_controller.cc
@@ -145,12 +145,11 @@ void PowerButtonController::OnDisplayModeChanged(
     const ui::DisplayConfigurator::DisplayStateList& display_states) {
   bool internal_display_off = false;
   bool external_display_on = false;
-  for (size_t i = 0; i < display_states.size(); ++i) {
-    const ui::DisplayConfigurator::DisplayState& state = display_states[i];
-    if (state.display->type() == ui::DISPLAY_CONNECTION_TYPE_INTERNAL) {
-      if (!state.display->current_mode())
+  for (const ui::DisplaySnapshot* display : display_states) {
+    if (display->type() == ui::DISPLAY_CONNECTION_TYPE_INTERNAL) {
+      if (!display->current_mode())
         internal_display_off = true;
-    } else if (state.display->current_mode()) {
+    } else if (display->current_mode()) {
       external_display_on = true;
     }
   }