[ash-md] Erases the pre-MD code path for Overview Mode

ash/wm/panels/panel_frame_view.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/panels/panel_frame_view.h"
 
 #include "ash/common/frame/caption_buttons/frame_caption_button_container_view.h"
 #include "ash/common/frame/default_header_painter.h"
 #include "ash/common/frame/frame_border_hit_test.h"
-#include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/wm_lookup.h"
 #include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window.h"
 #include "ui/base/hit_test.h"
 #include "ui/gfx/canvas.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
@@ skipping 121 matching lines @@
   HeaderPainter::Mode header_mode = paint_as_active
                                         ? HeaderPainter::MODE_ACTIVE
                                         : HeaderPainter::MODE_INACTIVE;
   header_painter_->PaintHeader(canvas, header_mode);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // PanelFrameView, ShellObserver overrides:
 
 void PanelFrameView::OnOverviewModeStarting() {
-  if (ash::MaterialDesignController::IsOverviewMaterial())
-    caption_button_container_->SetVisible(false);
+  caption_button_container_->SetVisible(false);
 }
 
 void PanelFrameView::OnOverviewModeEnded() {
-  if (ash::MaterialDesignController::IsOverviewMaterial())
-    caption_button_container_->SetVisible(true);
+  caption_button_container_->SetVisible(true);
 }
 
 }  // namespace ash