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

ash/wm/property_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/property_util.h"
 
 #include "ash/wm/window_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window.h"
+#include "ui/aura/window_property.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/gfx/rect.h"
 
+DECLARE_WINDOW_PROPERTY_TYPE(bool)
+
 namespace ash {
 
+namespace {
+
+const aura::WindowProperty<bool> kWindowTrackedByWorkspaceSplitProp = {true};
+
+}  // namespace
+
 void SetRestoreBounds(aura::Window* window, const gfx::Rect& bounds) {
   scoped_ptr<const gfx::Rect> old_bounds(GetRestoreBounds(window));
   window->SetProperty(aura::client::kRestoreBoundsKey, new gfx::Rect(bounds));
 }
 
 void SetRestoreBoundsIfNotSet(aura::Window* window) {
   if (!GetRestoreBounds(window))
     SetRestoreBounds(window, window->bounds());
 }
 
 const gfx::Rect* GetRestoreBounds(aura::Window* window) {
   return window->GetProperty(aura::client::kRestoreBoundsKey);
 }
 
 void ClearRestoreBounds(aura::Window* window) {
   scoped_ptr<const gfx::Rect> old_bounds(GetRestoreBounds(window));
   window->ClearProperty(aura::client::kRestoreBoundsKey);
 }
 
 void ToggleMaximizedState(aura::Window* window) {
   window->SetProperty(aura::client::kShowStateKey,
                       wm::IsWindowMaximized(window) ? ui::SHOW_STATE_NORMAL
                                                     : ui::SHOW_STATE_MAXIMIZED);
 }
 
+const aura::WindowProperty<bool>* const
+    kWindowTrackedByWorkspaceSplitPropKey = &kWindowTrackedByWorkspaceSplitProp;
+
+void SetTrackedByWorkspace(aura::Window* window, bool value) {
+  window->SetProperty(kWindowTrackedByWorkspaceSplitPropKey, value);
 }
+
+bool GetTrackedByWorkspace(aura::Window* window) {
+  return window->GetProperty(kWindowTrackedByWorkspaceSplitPropKey);
+}
+
+}