Add test for power_menu_button.

chrome/browser/chromeos/status/power_menu_button.cc

 // Copyright (c) 2009 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 "chrome/browser/chromeos/status/power_menu_button.h"
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "base/time.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
 #include "gfx/canvas.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 
 namespace chromeos {
 
 ////////////////////////////////////////////////////////////////////////////////
 // PowerMenuButton
 
 // static
 const int PowerMenuButton::kNumPowerImages = 12;
 
 PowerMenuButton::PowerMenuButton()
     : StatusAreaButton(this),
-      ALLOW_THIS_IN_INITIALIZER_LIST(power_menu_(this)) {
+      ALLOW_THIS_IN_INITIALIZER_LIST(power_menu_(this)),
+      icon_id_(-1) {
   UpdateIcon();
   CrosLibrary::Get()->GetPowerLibrary()->AddObserver(this);
 }
 
 PowerMenuButton::~PowerMenuButton() {
   CrosLibrary::Get()->GetPowerLibrary()->RemoveObserver(this);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // PowerMenuButton, menus::MenuModel implementation:
@@ skipping 80 matching lines @@
 void PowerMenuButton::DrawPowerIcon(gfx::Canvas* canvas, SkBitmap icon) {
   // Draw the battery icon 6 pixels down to center it.
   // Because the status icon is 24x24 but the images are 24x16.
   // But since the images are shifted up by 4 pixels, we draw at 6 pixels down.
   static const int kIconVerticalPadding = 6;
   canvas->DrawBitmapInt(icon, 0, kIconVerticalPadding);
 }
 
 void PowerMenuButton::UpdateIcon() {
   PowerLibrary* cros = CrosLibrary::Get()->GetPowerLibrary();
-  int id = IDR_STATUSBAR_BATTERY_UNKNOWN;
+  icon_id_ = IDR_STATUSBAR_BATTERY_UNKNOWN;
   if (CrosLibrary::Get()->EnsureLoaded()) {
     if (!cros->battery_is_present()) {
-      id = IDR_STATUSBAR_BATTERY_MISSING;
+      icon_id_ = IDR_STATUSBAR_BATTERY_MISSING;
     } else if (cros->line_power_on() && cros->battery_fully_charged()) {
-      id = IDR_STATUSBAR_BATTERY_CHARGED;
+      icon_id_ = IDR_STATUSBAR_BATTERY_CHARGED;
     } else {
       // If fully charged, always show 100% even if percentage is a bit less.
       double percent = cros->battery_fully_charged() ? 100 :
           cros->battery_percentage();
       // Gets the power image depending on battery percentage. Percentage is
       // from 0 to 100, so we need to convert that to 0 to kNumPowerImages - 1.
       int index = static_cast<int>(percent / 100.0 *
                   nextafter(static_cast<float>(kNumPowerImages), 0));
       // Make sure that index is between 0 and kNumWifiImages - 1
       if (index < 0)
         index = 0;
       if (index >= kNumPowerImages)
         index = kNumPowerImages - 1;
       if (cros->line_power_on())
-        id = IDR_STATUSBAR_BATTERY_CHARGING_1 + index;
+        icon_id_ = IDR_STATUSBAR_BATTERY_CHARGING_1 + index;
       else
-        id = IDR_STATUSBAR_BATTERY_DISCHARGING_1 + index;
+        icon_id_ = IDR_STATUSBAR_BATTERY_DISCHARGING_1 + index;
     }
   }
-  SetIcon(*ResourceBundle::GetSharedInstance().GetBitmapNamed(id));
+  SetIcon(*ResourceBundle::GetSharedInstance().GetBitmapNamed(icon_id_));
   SchedulePaint();
 }
 
 }  // namespace chromeos