Attempt 2: Allows tab dragging when maximized on aura. To fix it I made it so

ash/wm/window_util.cc

Index: ash/wm/window_util.cc
diff --git a/ash/wm/window_util.cc b/ash/wm/window_util.cc
index 5976a388dd1afc63d6c2c9220de086554bcdb186..da0ebf0becae74b3433665d45cc32e76a16bdab9 100644
--- a/ash/wm/window_util.cc
+++ b/ash/wm/window_util.cc
@@ -51,6 +51,13 @@ aura::Window* GetActivatableWindow(aura::Window* window) {
   return internal::ActivationController::GetActivatableWindow(window);
 }
 
+bool IsWindowNormal(aura::Window* window) {
+  return window->GetProperty(aura::client::kShowStateKey) ==
+          ui::SHOW_STATE_NORMAL ||
+      window->GetProperty(aura::client::kShowStateKey) ==
+          ui::SHOW_STATE_DEFAULT;
+}
+
 bool IsWindowMaximized(aura::Window* window) {
   return window->GetProperty(aura::client::kShowStateKey) ==
       ui::SHOW_STATE_MAXIMIZED;