exo: Fix dragging edge cases

components/exo/wm_helper.cc

Index: components/exo/wm_helper.cc
diff --git a/components/exo/wm_helper.cc b/components/exo/wm_helper.cc
index 6e4b495ba5c8ae3a802ed9575237223eae37bd78..38cf9e990bfd16ed61e8b38faaaaa2b6bf9f01a1 100644
--- a/components/exo/wm_helper.cc
+++ b/components/exo/wm_helper.cc
@@ -54,12 +54,12 @@ void WMHelper::RemoveCursorObserver(CursorObserver* observer) {
   cursor_observers_.RemoveObserver(observer);
 }
 
-void WMHelper::AddMaximizeModeObserver(MaximizeModeObserver* observer) {
-  maximize_mode_observers_.AddObserver(observer);
+void WMHelper::AddShellObserver(ShellObserver* observer) {
+  shell_observers_.AddObserver(observer);
 }
 
-void WMHelper::RemoveMaximizeModeObserver(MaximizeModeObserver* observer) {
-  maximize_mode_observers_.RemoveObserver(observer);
+void WMHelper::RemoveShellObserver(ShellObserver* observer) {
+  shell_observers_.RemoveObserver(observer);
 }
 
 void WMHelper::NotifyWindowActivated(aura::Window* gained_active,
@@ -85,13 +85,19 @@ void WMHelper::NotifyCursorSetChanged(ui::CursorSetType cursor_set) {
 }
 
 void WMHelper::NotifyMaximizeModeStarted() {
-  FOR_EACH_OBSERVER(MaximizeModeObserver, maximize_mode_observers_,
-                    OnMaximizeModeStarted());
+  FOR_EACH_OBSERVER(ShellObserver, shell_observers_, OnMaximizeModeStarted());
 }
 
 void WMHelper::NotifyMaximizeModeEnded() {
-  FOR_EACH_OBSERVER(MaximizeModeObserver, maximize_mode_observers_,
-                    OnMaximizeModeEnded());
+  FOR_EACH_OBSERVER(ShellObserver, shell_observers_, OnMaximizeModeEnded());
+}
+
+void WMHelper::NotifyOverviewModeStarted() {
+  FOR_EACH_OBSERVER(ShellObserver, shell_observers_, OnOverviewModeStarted());
+}
+
+void WMHelper::NotifyOverviewModeEnded() {
+  FOR_EACH_OBSERVER(ShellObserver, shell_observers_, OnOverviewModeEnded());
 }
 
 }  // namespace exo