Fix X11DesktopHandler::ActivateWindow on Unity for known user gestures

ui/views/widget/desktop_aura/desktop_native_widget_aura.h

 // 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.
 
 #ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_WIDGET_AURA_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_WIDGET_AURA_H_
 
 #include "base/memory/weak_ptr.h"
 #include "ui/aura/client/focus_change_observer.h"
 #include "ui/aura/window_delegate.h"
@@ skipping 124 matching lines @@
   void StackBelow(gfx::NativeView native_view) override;
   void SetShape(gfx::NativeRegion shape) override;
   void Close() override;
   void CloseNow() override;
   void Show() override;
   void Hide() override;
   void ShowMaximizedWithBounds(const gfx::Rect& restored_bounds) override;
   void ShowWithWindowState(ui::WindowShowState state) override;
   bool IsVisible() const override;
   void Activate() override;
+  void ActivateForUserGesture() override;
   void Deactivate() override;
   bool IsActive() const override;
   void SetAlwaysOnTop(bool always_on_top) override;
   bool IsAlwaysOnTop() const override;
   void SetVisibleOnAllWorkspaces(bool always_visible) override;
   void Maximize() override;
   void Minimize() override;
   bool IsMaximized() const override;
   bool IsMinimized() const override;
   void Restore() override;
@@ skipping 160 matching lines @@
   // The following factory is used for calls to close the NativeWidgetAura
   // instance.
   base::WeakPtrFactory<DesktopNativeWidgetAura> close_widget_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopNativeWidgetAura);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_WIDGET_AURA_H_