Linux Aura: Use managed tab dragging when possible (Reland)

ui/views/widget/desktop_aura/x11_desktop_window_move_client_managed.h

Index: ui/views/widget/desktop_aura/x11_desktop_window_move_client_managed.h
diff --git a/ui/views/widget/desktop_aura/x11_desktop_window_move_client_managed.h b/ui/views/widget/desktop_aura/x11_desktop_window_move_client_managed.h
new file mode 100644
index 0000000000000000000000000000000000000000..e941baa89bb74617ed4c9d2ff90d6d2d6cccebdb
--- /dev/null
+++ b/ui/views/widget/desktop_aura/x11_desktop_window_move_client_managed.h
@@ -0,0 +1,56 @@
+// Copyright 2016 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.
+
+#ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_X11_DESKTOP_WINDOW_MOVE_CLIENT_MANAGED_H_
+#define UI_VIEWS_WIDGET_DESKTOP_AURA_X11_DESKTOP_WINDOW_MOVE_CLIENT_MANAGED_H_
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "ui/events/platform/platform_event_dispatcher.h"
+#include "ui/views/views_export.h"
+#include "ui/wm/public/window_move_client.h"
+
+typedef unsigned long XID;
+
+namespace ui {
+class ScopedEventDispatcher;
+}
+
+namespace views {
+
+class VIEWS_EXPORT X11DesktopWindowMoveClientManaged
+    : public aura::client::WindowMoveClient,
+      public ui::PlatformEventDispatcher {
+ public:
+  X11DesktopWindowMoveClientManaged();
+  ~X11DesktopWindowMoveClientManaged() override;
+
+  // Overridden from ui::PlatformEventDispatcher:
+  bool CanDispatchEvent(const ui::PlatformEvent& event) override;
+  uint32_t DispatchEvent(const ui::PlatformEvent& event) override;
+
+  // Overridden from aura::client::WindowMoveClient:
+  aura::client::WindowMoveResult RunMoveLoop(
+      aura::Window* window,
+      const gfx::Vector2d& drag_offset,
+      aura::client::WindowMoveSource move_source) override;
+  void EndMoveLoop() override;
+
+ private:
+  // Are we running a nested message loop from RunMoveLoop()?
+  bool in_move_loop_;
+  std::unique_ptr<ui::ScopedEventDispatcher> nested_dispatcher_;
+
+  XID window_;
+
+  base::Closure quit_closure_;
+
+  base::WeakPtrFactory<X11DesktopWindowMoveClientManaged> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(X11DesktopWindowMoveClientManaged);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_X11_DESKTOP_WINDOW_MOVE_CLIENT_MANAGED_H_