chromeos: removes some dead code

MASH_DEPRECATED is never set anymore.

BUG=640773
TEST=none

Change-Id: Iab913023f56e7f832cb987b10b5725d55ccc1ead
Reviewed-on: https://chromium-review.googlesource.com/1176072Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583287}

ash/wm/wm_toplevel_window_event_handler.cc

@@ -4,7 +4,6 @@
 
 #include "ash/wm/wm_toplevel_window_event_handler.h"
 
-#include "ash/public/cpp/config.h"
 #include "ash/shell.h"
 #include "ash/wm/resize_shadow_controller.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
@@ -60,11 +59,6 @@ bool CanStartOneFingerDrag(int window_component) {
 }
 
 void ShowResizeShadow(aura::Window* window, int component) {
-  if (Shell::GetAshConfig() == Config::MASH_DEPRECATED) {
-    // TODO: http://crbug.com/640773.
-    return;
-  }
-
   // Window resize in tablet mode is disabled (except in splitscreen).
   if (Shell::Get()
           ->tablet_mode_controller()
@@ -79,11 +73,6 @@ void ShowResizeShadow(aura::Window* window, int component) {
 }
 
 void HideResizeShadow(aura::Window* window) {
-  if (Shell::GetAshConfig() == Config::MASH_DEPRECATED) {
-    // TODO: http://crbug.com/640773.
-    return;
-  }
-
   ResizeShadowController* resize_shadow_controller =
       Shell::Get()->resize_shadow_controller();
   if (resize_shadow_controller)