Remove usage of FOR_EACH_OBSERVER macro in ash/common

ash/common/wm/window_state.cc

Index: ash/common/wm/window_state.cc
diff --git a/ash/common/wm/window_state.cc b/ash/common/wm/window_state.cc
index e3b5cbb9d223309f4d1a012947c0a5d141ab059b..c6654c0c265102a76890031d58d65bbe792727cd 100644
--- a/ash/common/wm/window_state.cc
+++ b/ash/common/wm/window_state.cc
@@ -351,14 +351,14 @@ void WindowState::UpdateWindowShowStateFromStateType() {
 
 void WindowState::NotifyPreStateTypeChange(
     WindowStateType old_window_state_type) {
-  FOR_EACH_OBSERVER(WindowStateObserver, observer_list_,
-                    OnPreWindowStateTypeChange(this, old_window_state_type));
+  for (auto& observer : observer_list_)
+    observer.OnPreWindowStateTypeChange(this, old_window_state_type);
 }
 
 void WindowState::NotifyPostStateTypeChange(
     WindowStateType old_window_state_type) {
-  FOR_EACH_OBSERVER(WindowStateObserver, observer_list_,
-                    OnPostWindowStateTypeChange(this, old_window_state_type));
+  for (auto& observer : observer_list_)
+    observer.OnPostWindowStateTypeChange(this, old_window_state_type);
 }
 
 void WindowState::SetBoundsDirect(const gfx::Rect& bounds) {