Sets the max height of ImeMenuTray.

ash/common/system/chromeos/ime_menu/ime_menu_tray.cc

 // Copyright 2016 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/ime_menu/ime_menu_tray.h"
 
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shelf/wm_shelf_util.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/system/chromeos/ime_menu/ime_list_view.h"
+#include "ash/common/system/tray/fixed_sized_scroll_view.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_popup_header_button.h"
 #include "ash/common/system/tray/tray_utils.h"
 #include "ash/common/wm_lookup.h"
 #include "ash/common/wm_root_window_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 #include "base/strings/utf_string_conversions.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/box_layout.h"
 
 namespace ash {
 
 namespace {
 
+// Returns the max height of ImeListView.
+int GetImeListViewMaxHeight() {
+  return GetTrayConstant(TRAY_POPUP_ITEM_HEIGHT) * 7;

[James Cook, 2016/08/23 15:47:12]

nit: Use a named constant for 7, like const int max_items = 7.

+}
+
 class ImeMenuLabel : public views::Label {
  public:
   ImeMenuLabel() {}
   ~ImeMenuLabel() override {}
 
   // views:Label:
   gfx::Size GetPreferredSize() const override {
     return gfx::Size(kTrayImeIconSize, kTrayImeIconSize);
   }
   int GetHeightForWidth(int width) const override { return kTrayImeIconSize; }
@@ skipping 210 matching lines @@
       kTrayPopupMinWidth, kTrayPopupMaxWidth);
   init_params.first_item_has_no_margin = true;
   init_params.can_activate = true;
   init_params.close_on_deactivate = true;
 
   views::TrayBubbleView* bubble_view =
       views::TrayBubbleView::Create(tray_container(), this, &init_params);
   bubble_view->set_margins(gfx::Insets(7, 0, 0, 0));
   bubble_view->SetArrowPaintType(views::BubbleBorder::PAINT_NONE);
 
+  ImeListView* ime_list_view =
+      new ImeListView(nullptr, false, ImeListView::SHOW_SINGLE_IME);
+  if (ime_list_view->scroll_content()->height() > GetImeListViewMaxHeight()) {
+    ime_list_view->scroller()->SetFixedSize(
+        gfx::Size(kTrayPopupMaxWidth, GetImeListViewMaxHeight()));
+  }
   // Adds IME list to the bubble.
-  bubble_view->AddChildView(
-      new ImeListView(nullptr, false, ImeListView::SHOW_SINGLE_IME));
+  bubble_view->AddChildView(ime_list_view);
 
   // Adds IME buttons to the bubble if needed.
   LoginStatus login =
       WmShell::Get()->system_tray_delegate()->GetUserLoginStatus();
   if (login != LoginStatus::NOT_LOGGED_IN && login != LoginStatus::LOCKED &&
       !WmShell::Get()->GetSessionStateDelegate()->IsInSecondaryLoginScreen())
     bubble_view->AddChildView(new ImeButtonsView(false, false, false, true));
 
   bubble_.reset(new ash::TrayBubbleWrapper(this, bubble_view));
   SetDrawBackgroundAsActive(true);
 }
 
 void ImeMenuTray::HideImeMenuBubble() {
   bubble_.reset();
   SetDrawBackgroundAsActive(false);
 }
 
 }  // namespace ash