Only drag or maximize / restore when event has not yet been handled.

ash/wm/toplevel_window_event_handler.cc

Index: ash/wm/toplevel_window_event_handler.cc
diff --git a/ash/wm/toplevel_window_event_handler.cc b/ash/wm/toplevel_window_event_handler.cc
index 635860f356cf633efd1c0d37e74e688f5af6313b..4e8fe39fc9ff38d4a469ae34dbc4f7217dd5bb65 100644
--- a/ash/wm/toplevel_window_event_handler.cc
+++ b/ash/wm/toplevel_window_event_handler.cc
@@ -184,6 +184,8 @@ void ToplevelWindowEventHandler::OnGestureEvent(ui::GestureEvent* event) {
 
   switch (event->type()) {
     case ui::ET_GESTURE_TAP_DOWN: {
+      if (event->handled())
+        return;
       int component =
           target->delegate()->GetNonClientComponent(event->location());
       if (!(WindowResizer::GetBoundsChangeForWindowComponent(component) &
@@ -203,7 +205,7 @@ void ToplevelWindowEventHandler::OnGestureEvent(ui::GestureEvent* event) {
       return;
     }
     case ui::ET_GESTURE_SCROLL_BEGIN: {
-      if (in_gesture_drag_)
+      if (in_gesture_drag_ || event->handled())
         return;
       int component =
           target->delegate()->GetNonClientComponent(event->location());
@@ -352,7 +354,7 @@ void ToplevelWindowEventHandler::CompleteDrag(DragCompletionStatus status) {
 void ToplevelWindowEventHandler::HandleMousePressed(
     aura::Window* target,
     ui::MouseEvent* event) {
-  if (event->phase() != ui::EP_PRETARGET)
+  if (event->phase() != ui::EP_PRETARGET || event->handled())
     return;
 
   // We also update the current window component here because for the