Clean up MASH_DEPRECATED in shelf auto-hide code

I verified that autohide works properly under mash with mouse gestures,
touch gestures, and bezel gestures.

Bug: 636647, 631216
Test: ash_unittests, manual on device
Change-Id: I368a72a96dbac9791eb67ede9adc739e1d9079fb
Reviewed-on: https://chromium-review.googlesource.com/1134405Reviewed-by: Michael Wasserman <msw@chromium.org>
Commit-Queue: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574433}

ash/shelf/shelf.cc

@@ -7,7 +7,6 @@
 #include <memory>
 
 #include "ash/app_list/app_list_controller_impl.h"
-#include "ash/public/cpp/config.h"
 #include "ash/public/cpp/shelf_item_delegate.h"
 #include "ash/public/cpp/shelf_model.h"
 #include "ash/public/cpp/shell_window_ids.h"
@@ -29,7 +28,6 @@ namespace ash {
 // Shelf::AutoHideEventHandler -----------------------------------------------
 
 // Forwards mouse and gesture events to ShelfLayoutManager for auto-hide.
-// TODO(mash): Add similar event handling support for mash.
 class Shelf::AutoHideEventHandler : public ui::EventHandler {
  public:
   explicit AutoHideEventHandler(ShelfLayoutManager* shelf_layout_manager)
@@ -57,12 +55,9 @@ class Shelf::AutoHideEventHandler : public ui::EventHandler {
 
 // Shelf ---------------------------------------------------------------------
 
-Shelf::Shelf() : shelf_locking_manager_(this) {
-  // TODO: ShelfBezelEventHandler needs to work with mus too.
-  // http://crbug.com/636647
-  if (Shell::GetAshConfig() != Config::MASH_DEPRECATED)
-    bezel_event_handler_ = std::make_unique<ShelfBezelEventHandler>(this);
-}
+Shelf::Shelf()
+    : shelf_locking_manager_(this),
+      bezel_event_handler_(std::make_unique<ShelfBezelEventHandler>(this)) {}
 
 Shelf::~Shelf() = default;
 
@@ -348,8 +343,7 @@ void Shelf::WillChangeVisibilityState(ShelfVisibilityState new_state) {
     observer.WillChangeVisibilityState(new_state);
   if (new_state != SHELF_AUTO_HIDE) {
     auto_hide_event_handler_.reset();
-  } else if (!auto_hide_event_handler_ &&
-             Shell::GetAshConfig() != Config::MASH_DEPRECATED) {
+  } else if (!auto_hide_event_handler_) {
     auto_hide_event_handler_ =
         std::make_unique<AutoHideEventHandler>(shelf_layout_manager());
   }

ash/shelf/shelf.h

@@ -187,11 +187,9 @@ class ASH_EXPORT Shelf : public ShelfLayoutManagerObserver {
   base::ObserverList<ShelfObserver> observers_;
 
   // Forwards mouse and gesture events to ShelfLayoutManager for auto-hide.
-  // TODO(mash): Facilitate simliar functionality in mash: crbug.com/631216
   std::unique_ptr<AutoHideEventHandler> auto_hide_event_handler_;
 
   // Forwards touch gestures on a bezel sensor to the shelf.
-  // TODO(mash): Facilitate simliar functionality in mash: crbug.com/636647
   std::unique_ptr<ShelfBezelEventHandler> bezel_event_handler_;
 
   // True while the animation to enter or exit tablet mode is running. Sometimes