Remove some pre-md code and assets.

ash/common/system/chromeos/brightness/tray_brightness.cc

 // Copyright 2013 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/common/system/chromeos/brightness/tray_brightness.h"
 
 #include <algorithm>
 
-#include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shell_observer.h"
 #include "ash/common/system/brightness_control_delegate.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_popup_utils.h"
 #include "ash/common/system/tray/tri_view.h"
 #include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/resources/grit/ash_resources.h"
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/shell.h"
@@ skipping 76 matching lines @@
       last_percent_(initial_percent) {
   SetLayoutManager(new views::FillLayout);
   // Use CreateMultiTargetRowView() instead of CreateDefaultRowView() because
   // that's what the audio row uses and we want the two rows to layout with the
   // same insets.
   TriView* tri_view = TrayPopupUtils::CreateMultiTargetRowView();
   AddChildView(tri_view);
 
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
   views::ImageView* icon = TrayPopupUtils::CreateMainImageView();
-  if (MaterialDesignController::IsSystemTrayMenuMaterial()) {
-    icon->SetImage(
-        gfx::CreateVectorIcon(kSystemMenuBrightnessIcon, kMenuIconColor));
-  } else {
-    icon->SetImage(
-        rb.GetImageNamed(IDR_AURA_UBER_TRAY_BRIGHTNESS).ToImageSkia());
-  }
+  icon->SetImage(
+      gfx::CreateVectorIcon(kSystemMenuBrightnessIcon, kMenuIconColor));
   tri_view->AddView(TriView::Container::START, icon);
 
   slider_ = TrayPopupUtils::CreateSlider(this);
   slider_->SetValue(static_cast<float>(initial_percent / 100.0));
   slider_->SetAccessibleName(
       rb.GetLocalizedString(IDS_ASH_STATUS_TRAY_BRIGHTNESS));
   tri_view->AddView(TriView::Container::CENTER, slider_);
 
   if (is_default_view_) {
     Shell::GetInstance()->AddShellObserver(this);
@@ skipping 152 matching lines @@
   if (!display::Display::HasInternalDisplay())
     return;
 
   if (brightness_view_ && brightness_view_->visible())
     SetDetailedViewCloseDelay(kTrayPopupAutoCloseDelayInSeconds);
   else
     ShowDetailedView(kTrayPopupAutoCloseDelayInSeconds, false);
 }
 
 }  // namespace ash