Remove "top_down" flag in the message center code

ui/message_center/views/message_list_view.cc

 // Copyright (c) 2015 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 "base/command_line.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ui/gfx/animation/slide_animation.h"
 #include "ui/message_center/message_center_style.h"
 #include "ui/message_center/message_center_switches.h"
 #include "ui/message_center/views/message_center_view.h"
 #include "ui/message_center/views/message_list_view.h"
 #include "ui/message_center/views/message_view.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/widget/widget.h"
 
 namespace message_center {
 
 namespace {
 const int kAnimateClearingNextNotificationDelayMS = 40;
 }  // namespace
 
-MessageListView::MessageListView(bool top_down)
+MessageListView::MessageListView()
     : reposition_top_(-1),
       fixed_height_(0),
       has_deferred_task_(false),
       clear_all_started_(false),
-      top_down_(top_down),
       animator_(this),
       quit_message_loop_after_animation_for_test_(false),
       weak_ptr_factory_(this) {
   views::BoxLayout* layout =
       new views::BoxLayout(views::BoxLayout::kVertical, 0, 0, 1);
   layout->SetDefaultFlex(1);
   SetLayoutManager(layout);
 
   // Set the margin to 0 for the layout. BoxLayout assumes the same margin
   // for top and bottom, but the bottom margin here should be smaller
   // because of the shadow of message view. Use an empty border instead
   // to provide this margin.
   gfx::Insets shadow_insets = MessageView::GetShadowInsets();
   set_background(
       views::Background::CreateSolidBackground(kMessageCenterBackgroundColor));
   SetBorder(views::CreateEmptyBorder(
-      top_down ? 0 : kMarginBetweenItems - shadow_insets.top(),    /* top */
-      kMarginBetweenItems - shadow_insets.left(),                  /* left */
-      top_down ? kMarginBetweenItems - shadow_insets.bottom() : 0, /* bottom */
+      kMarginBetweenItems - shadow_insets.top(), /* top */
+      kMarginBetweenItems - shadow_insets.left(), /* left */
+      0, /* bottom */
       kMarginBetweenItems - shadow_insets.right() /* right */));
   animator_.AddObserver(this);
 }
 
 MessageListView::~MessageListView() {
   animator_.RemoveObserver(this);
 }
 
 void MessageListView::Layout() {
   if (animator_.IsAnimating())
@@ skipping 219 matching lines @@
   }
 
   if (!clearing_all_views_.empty()) {
     AnimateClearingOneNotification();
     return;
   }
 
   int new_height = GetHeightForWidth(child_area.width() + GetInsets().width());
   SetSize(gfx::Size(child_area.width() + GetInsets().width(), new_height));
 
-  if (top_down_ ||
-      base::CommandLine::ForCurrentProcess()->HasSwitch(
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableMessageCenterAlwaysScrollUpUponNotificationRemoval))
     AnimateNotificationsBelowTarget();
   else
     AnimateNotificationsAboveTarget();
 
   adding_views_.clear();
   deleting_views_.clear();
 
   if (!animator_.IsAnimating() && GetWidget())
     GetWidget()->SynthesizeMouseMoveEvent();
@@ skipping 177 matching lines @@
         base::TimeDelta::FromMilliseconds(
             kAnimateClearingNextNotificationDelayMS));
   }
 }
 
 void MessageListView::SetRepositionTargetForTest(const gfx::Rect& target_rect) {
   SetRepositionTarget(target_rect);
 }
 
 }  // namespace message_center