Adds a tooltip to the frame maximize button.

ash/wm/workspace/frame_maximize_button.cc

 // Copyright (c) 2012 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/wm/workspace/frame_maximize_button.h"
 
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/wm/property_util.h"
 #include "ash/launcher/launcher.h"
 #include "ash/wm/workspace/phantom_window_controller.h"
 #include "ash/wm/workspace/snap_sizer.h"
+#include "grit/ash_strings.h"
 #include "grit/ui_resources.h"
 #include "ui/aura/event.h"
 #include "ui/aura/event_filter.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/non_client_view.h"
 
 using ash::internal::SnapSizer;
 
 namespace ash {
 
@@ skipping 65 matching lines @@
 
 FrameMaximizeButton::FrameMaximizeButton(views::ButtonListener* listener,
                                          views::NonClientFrameView* frame)
     : ImageButton(listener),
       frame_(frame),
       is_snap_enabled_(false),
       exceeded_drag_threshold_(false),
       snap_type_(SNAP_NONE) {
   // TODO(sky): nuke this. It's temporary while we don't have good images.
   SetImageAlignment(ALIGN_LEFT, ALIGN_BOTTOM);
+  SetTooltipText(l10n_util::GetStringUTF16(IDS_FRAME_MAXIMIZE_BUTTON_TOOLTIP));
 }
 
 FrameMaximizeButton::~FrameMaximizeButton() {
 }
 
 bool FrameMaximizeButton::OnMousePressed(const views::MouseEvent& event) {
   is_snap_enabled_ = event.IsLeftMouseButton();
   if (is_snap_enabled_) {
     snap_sizer_.reset(NULL);
     InstallEventFilter();
@@ skipping 211 matching lines @@
       break;
     case SNAP_MINIMIZE:
       frame_->GetWidget()->Minimize();
       break;
     default:
       NOTREACHED();
   }
 }
 
 }  // namespace ash