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

ash/wm/window_util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/window_util.h"
 
 #include "ash/shell.h"
 #include "ash/wm/activation_controller.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/client/aura_constants.h"
@@ skipping 33 matching lines @@
 
 aura::Window* GetActiveWindow() {
   return aura::client::GetActivationClient(Shell::GetRootWindow())->
       GetActiveWindow();
 }
 
 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;
 }
 
 bool IsWindowFullscreen(aura::Window* window) {
   return window->GetProperty(aura::client::kShowStateKey) ==
       ui::SHOW_STATE_FULLSCREEN;
 }
 
@@ skipping 18 matching lines @@
 void SetOpenWindowSplit(aura::Window* window, bool value) {
   window->SetProperty(kOpenWindowSplitKey, value);
 }
 
 bool GetOpenWindowSplit(aura::Window* window) {
   return window->GetProperty(kOpenWindowSplitKey);
 }
 
 }  // namespace wm
 }  // namespace ash