Gut ash::MaterialDesignController, and remove the about:flags entry.

ash/common/wm/overview/window_selector_item.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/wm/overview/window_selector_item.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "ash/common/material_design/material_design_controller.h"
@@ skipping 655 matching lines @@
       this, label_view_, close_button_, background_view_);
   item_widget_->SetContentsView(caption_container_view_);
   label_view_->SetVisible(false);
   item_widget_->SetOpacity(0);
   item_widget_->Show();
 
   // TODO(varkha): Restore shadows when programmatic shadows exist.
   // Note: current shadow implementation does not allow proper animation when
   // the parent layer bounds change during the animation since
   // Shadow::UpdateLayerBounds() only happens before the animation starts.
-  if (ash::MaterialDesignController::GetMode() ==
-      ash::MaterialDesignController::Mode::MATERIAL_EXPERIMENTAL) {
-    shadow_.reset(new ::wm::Shadow());
-    shadow_->Init(::wm::ShadowElevation::MEDIUM);
-    shadow_->layer()->SetVisible(true);
-    item_widget_->GetLayer()->Add(shadow_->layer());
-  }
+#if 0

[tdanderson, 2017/02/13 17:36:28]

Just delete this code instead.

[Evan Stade, 2017/02/13 17:41:01]

there's other related code throughout this file (behind if (shadow_)) -- Valery
are you OK with deleting it all?

[varkha, 2017/02/13 17:44:01]

Yes, please go ahead. The shadow was barely visible with the colors we use in
any case.

[Evan Stade, 2017/02/13 17:52:24]

indeed, it was supposed to be there for Alt+Tab too but I couldn't see it no
matter how much I squinted so I never added it.

[Evan Stade, 2017/02/13 19:29:42]

Done.

+  shadow_.reset(new ::wm::Shadow());
+  shadow_->Init(::wm::ShadowElevation::MEDIUM);
+  shadow_->layer()->SetVisible(true);
+  item_widget_->GetLayer()->Add(shadow_->layer());
+#endif
   item_widget_->GetLayer()->SetMasksToBounds(false);
 }
 
 void WindowSelectorItem::UpdateHeaderLayout(
     HeaderFadeInMode mode,
     OverviewAnimationType animation_type) {
   gfx::Rect transformed_window_bounds = root_window_->ConvertRectFromScreen(
       transform_window_.GetTransformedBounds());
 
   gfx::Rect label_rect(close_button_->GetPreferredSize());
@@ skipping 99 matching lines @@
 
 gfx::SlideAnimation* WindowSelectorItem::GetBackgroundViewAnimation() {
   return background_view_ ? background_view_->animation() : nullptr;
 }
 
 WmWindow* WindowSelectorItem::GetOverviewWindowForMinimizedStateForTest() {
   return transform_window_.GetOverviewWindowForMinimizedState();
 }
 
 }  // namespace ash