Updates the display message in the uber tray.

This CL contains the following fixes:
- shows the notification for display rotation / ui_scale
- adds (width x height) annotation to the display if something
  has been edited
- shows the internal display's status if something for the internal
  display has been edited and no external display is connected
- shows the tooltip text to provide the status of both internal and
  extrenal displays at the same time

This CL does not contain:
- the feature to prevent notification when the settings change happens
  from chrome://settings/display

I think we can achieve this by suppressing the notification when
the current active tab is chrome://settings/display, but anyways
it'll be done in another CL. That is marked as a TODO.

BUG=250650, 246271

Review URL: https://chromiumcodereview.appspot.com/17445002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207998 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 580 insertions, 115 deletions

diff --git a/ash/ash.gyp b/ash/ash.gyp
index 6821ed0..32e8cfd 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -698,6 +698,7 @@
         'shell/window_watcher_unittest.cc',
         'system/chromeos/network/network_state_notifier_unittest.cc',
         'system/chromeos/power/tray_power_unittest.cc',
+        'system/chromeos/tray_display_unittest.cc',
         'system/tray/system_tray_unittest.cc',
         'system/user/tray_user_unittest.cc',
         'system/web_notification/web_notification_tray_unittest.cc',
diff --git a/ash/ash_strings.grd b/ash/ash_strings.grd
index 53b2547..d16238a 100644
--- a/ash/ash_strings.grd
+++ b/ash/ash_strings.grd
@@ -321,6 +321,15 @@ Press Ctrl+Alt+Z to disable.
       <message name="IDS_ASH_STATUS_TRAY_DISPLAY_DOCKED" desc="The label used in the tray to show that the current status is docked mode.">
 	Dock mode
       </message>
+      <message name="IDS_ASH_STATUS_TRAY_DISPLAY_RESOLUTION_CHANGED" desc="The label used in the tray to notify that the display resolution settings has changed.">
+	<ph name="DISPLAY_NAME">$1</ph> has been resized to <ph name="RESOLUTION">$2</ph>
+      </message>
+      <message name="IDS_ASH_STATUS_TRAY_DISPLAY_ROTATED" desc="The label used in the tray to notify that the display rotation settings has changed.">
+	<ph name="DISPLAY_NAME">$1</ph> has been rotated
+      </message>
+      <message name="IDS_ASH_STATUS_TRAY_DISPLAY_SINGLE_DISPLAY" desc="The label used in the tray to show the current display's configuration if there is a single display">
+	<ph name="DISPLAY_NAME">$1</ph>: <ph name="RESOLUTION">$2</ph>
+      </message>
       <message name="IDS_ASH_STATUS_TRAY_UNKNOWN_DISPLAY_NAME" desc="Label shown in tray for a display whose name is unknown.">
 	Unknown Display
       </message>
diff --git a/ash/system/chromeos/tray_display.cc b/ash/system/chromeos/tray_display.cc
index cf3ca84..484e0d2 100644
--- a/ash/system/chromeos/tray_display.cc
+++ b/ash/system/chromeos/tray_display.cc
@@ -7,6 +7,7 @@
 #include "ash/display/display_controller.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
+#include "ash/system/tray/actionable_view.h"
 #include "ash/system/tray/fixed_sized_image_view.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_delegate.h"
@@ -17,6 +18,7 @@
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/box_layout.h"
 
@@ -24,26 +26,34 @@ namespace ash {
 namespace internal {
 namespace {
 
-TrayDisplayMode GetCurrentTrayDisplayMode() {
-  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
-  if (display_manager->GetNumDisplays() > 1)
-    return TRAY_DISPLAY_EXTENDED;
+bool display_notifications_disabled = false;
 
-  if (display_manager->IsMirrored())
-    return TRAY_DISPLAY_MIRRORED;
+DisplayManager* GetDisplayManager() {
+  return Shell::GetInstance()->display_manager();
+}
 
-  int64 first_id = display_manager->first_display_id();
-  if (display_manager->HasInternalDisplay() &&
-      !display_manager->IsInternalDisplayId(first_id)) {
-    return TRAY_DISPLAY_DOCKED;
-  }
+base::string16 GetDisplayName(int64 display_id) {
+  return UTF8ToUTF16(GetDisplayManager()->GetDisplayNameForId(display_id));
+}
+
+base::string16 GetDisplaySize(int64 display_id) {
+  return UTF8ToUTF16(
+      GetDisplayManager()->GetDisplayForId(display_id).size().ToString());
+}
+
+bool ShouldShowResolution(int64 display_id) {
+  if (!GetDisplayManager()->GetDisplayForId(display_id).is_valid())
+    return false;
 
-  return TRAY_DISPLAY_SINGLE;
+  const DisplayInfo& display_info =
+      GetDisplayManager()->GetDisplayInfo(display_id);
+  return display_info.rotation() != gfx::Display::ROTATE_0 ||
+      display_info.ui_scale() != 1.0f;
 }
 
 // Returns the name of the currently connected external display.
 base::string16 GetExternalDisplayName() {
-  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  DisplayManager* display_manager = GetDisplayManager();
   int64 external_id = display_manager->mirrored_display().id();
 
   if (external_id == gfx::Display::kInvalidDisplayID) {
@@ -56,82 +66,64 @@ base::string16 GetExternalDisplayName() {
       }
     }
   }
-  if (external_id != gfx::Display::kInvalidDisplayID)
-    return UTF8ToUTF16(display_manager->GetDisplayNameForId(external_id));
-  return l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_UNKNOWN_DISPLAY_NAME);
-}
 
-class DisplayViewBase {
- public:
-  DisplayViewBase(user::LoginStatus login_status)
-      : login_status_(login_status) {
-    label_ = new views::Label();
-    label_->SetMultiLine(true);
-    label_->SetHorizontalAlignment(gfx::ALIGN_LEFT);
-  }
+  if (external_id == gfx::Display::kInvalidDisplayID)
+    return l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_UNKNOWN_DISPLAY_NAME);
 
-  virtual ~DisplayViewBase() {
-  }
+  // The external display name may have an annotation of "(width x height)" in
+  // case that the display is rotated or its resolution is changed.
+  base::string16 name = GetDisplayName(external_id);
+  if (ShouldShowResolution(external_id))
+    name += UTF8ToUTF16(" (") + GetDisplaySize(external_id) + UTF8ToUTF16(")");
 
- protected:
-  void OpenSettings() {
-    if (login_status_ == ash::user::LOGGED_IN_USER ||
-        login_status_ == ash::user::LOGGED_IN_OWNER ||
-        login_status_ == ash::user::LOGGED_IN_GUEST) {
-      ash::Shell::GetInstance()->system_tray_delegate()->ShowDisplaySettings();
+  return name;
+}
+
+base::string16 GetTrayDisplayMessage() {
+  DisplayManager* display_manager = GetDisplayManager();
+  if (display_manager->GetNumDisplays() > 1) {
+    if (GetDisplayManager()->HasInternalDisplay()) {
+      return l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED, GetExternalDisplayName());
     }
+    return l10n_util::GetStringUTF16(
+        IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED_NO_INTERNAL);
   }
 
-  bool UpdateLabelText() {
-    switch (GetCurrentTrayDisplayMode()) {
-      case TRAY_DISPLAY_SINGLE:
-        // TODO(oshima|mukai): Support single display mode for overscan
-        // alignment.
-        return false;
-      case TRAY_DISPLAY_EXTENDED:
-        if (Shell::GetInstance()->display_manager()->HasInternalDisplay()) {
-          label_->SetText(l10n_util::GetStringFUTF16(
-              IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED, GetExternalDisplayName()));
-        } else {
-          label_->SetText(l10n_util::GetStringUTF16(
-              IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED_NO_INTERNAL));
-        }
-        break;
-      case TRAY_DISPLAY_MIRRORED:
-        if (Shell::GetInstance()->display_manager()->HasInternalDisplay()) {
-          label_->SetText(l10n_util::GetStringFUTF16(
-              IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING, GetExternalDisplayName()));
-        } else {
-          label_->SetText(l10n_util::GetStringUTF16(
-              IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING_NO_INTERNAL));
-        }
-        break;
-      case TRAY_DISPLAY_DOCKED:
-        label_->SetText(l10n_util::GetStringUTF16(
-            IDS_ASH_STATUS_TRAY_DISPLAY_DOCKED));
-        break;
+  if (display_manager->IsMirrored()) {
+    if (GetDisplayManager()->HasInternalDisplay()) {
+      return l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING, GetExternalDisplayName());
     }
-    return true;
+    return l10n_util::GetStringUTF16(
+        IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING_NO_INTERNAL);
   }
 
-  views::Label* label() { return label_; }
+  int64 first_id = display_manager->first_display_id();
+  if (display_manager->HasInternalDisplay() &&
+      !display_manager->IsInternalDisplayId(first_id)) {
+    return l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_DISPLAY_DOCKED);
+  }
 
- private:
-  user::LoginStatus login_status_;
-  views::Label* label_;
+  return base::string16();
+}
 
-  DISALLOW_COPY_AND_ASSIGN(DisplayViewBase);
-};
+void OpenSettings(user::LoginStatus login_status) {
+  if (login_status == ash::user::LOGGED_IN_USER ||
+      login_status == ash::user::LOGGED_IN_OWNER ||
+      login_status == ash::user::LOGGED_IN_GUEST) {
+    ash::Shell::GetInstance()->system_tray_delegate()->ShowDisplaySettings();
+  }
+}
 
 }  // namespace
 
-class DisplayView : public DisplayViewBase,
-                    public ash::internal::ActionableView {
+class DisplayView : public ash::internal::ActionableView {
  public:
   explicit DisplayView(user::LoginStatus login_status)
-      : DisplayViewBase(login_status) {
-    SetLayoutManager(new
-        views::BoxLayout(views::BoxLayout::kHorizontal,
+      : login_status_(login_status) {
+    SetLayoutManager(new views::BoxLayout(
+        views::BoxLayout::kHorizontal,
         ash::kTrayPopupPaddingHorizontal, 0,
         ash::kTrayPopupPaddingBetweenItems));
 
@@ -141,70 +133,111 @@ class DisplayView : public DisplayViewBase,
     image_->SetImage(
         bundle.GetImageNamed(IDR_AURA_UBER_TRAY_DISPLAY).ToImageSkia());
     AddChildView(image_);
-    AddChildView(label());
+
+    label_ = new views::Label();
+    label_->SetMultiLine(true);
+    label_->SetHorizontalAlignment(gfx::ALIGN_LEFT);
+    AddChildView(label_);
     Update();
   }
 
   virtual ~DisplayView() {}
 
   void Update() {
-    SetVisible(UpdateLabelText());
+    base::string16 message = GetTrayDisplayMessage();
+    if (message.empty())
+      message = GetInternalDisplayInfo();
+    SetVisible(!message.empty());
+    label_->SetText(message);
+  }
+
+  views::Label* label() { return label_; }
+
+  // Overridden from views::View.
+  virtual bool GetTooltipText(const gfx::Point& p,
+                              base::string16* tooltip) const OVERRIDE {
+    base::string16 tray_message = GetTrayDisplayMessage();
+    base::string16 internal_message = GetInternalDisplayInfo();
+    if (tray_message.empty() && internal_message.empty())
+      return false;
+
+    *tooltip = tray_message + ASCIIToUTF16("\n") + internal_message;
+    return true;
   }
 
  private:
+  base::string16 GetInternalDisplayInfo() const {
+    int64 first_id = GetDisplayManager()->first_display_id();
+    if (!ShouldShowResolution(first_id))
+      return base::string16();
+
+    return l10n_util::GetStringFUTF16(
+        IDS_ASH_STATUS_TRAY_DISPLAY_SINGLE_DISPLAY,
+        GetDisplayName(first_id),
+        GetDisplaySize(first_id));
+  }
+
   // Overridden from ActionableView.
   virtual bool PerformAction(const ui::Event& event) OVERRIDE {
-    OpenSettings();
+    OpenSettings(login_status_);
     return true;
   }
 
   virtual void OnBoundsChanged(const gfx::Rect& previous_bounds) OVERRIDE {
     int label_max_width = bounds().width() - kTrayPopupPaddingHorizontal * 2 -
         kTrayPopupPaddingBetweenItems - image_->GetPreferredSize().width();
-    label()->SizeToFit(label_max_width);
+    label_->SizeToFit(label_max_width);
     PreferredSizeChanged();
   }
 
+  user::LoginStatus login_status_;
   views::ImageView* image_;
+  views::Label* label_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayView);
 };
 
-class DisplayNotificationView : public DisplayViewBase,
-                                public TrayNotificationView {
+class DisplayNotificationView : public TrayNotificationView {
  public:
   DisplayNotificationView(user::LoginStatus login_status,
-                          TrayDisplay* tray_item)
-      : DisplayViewBase(login_status),
-        TrayNotificationView(tray_item, IDR_AURA_UBER_TRAY_DISPLAY) {
-    InitView(label());
+                          TrayDisplay* tray_item,
+                          const base::string16& message)
+      : TrayNotificationView(tray_item, IDR_AURA_UBER_TRAY_DISPLAY),
+        login_status_(login_status) {
     StartAutoCloseTimer(kTrayPopupAutoCloseDelayForTextInSeconds);
-    Update();
+    Update(message);
   }
 
   virtual ~DisplayNotificationView() {}
 
-  void Update() {
-    if (UpdateLabelText())
-      RestartAutoCloseTimer();
-    else
+  void Update(const base::string16& message) {
+    if (message.empty()) {
       owner()->HideNotificationView();
+    } else {
+      views::Label* label = new views::Label(message);
+      label->SetMultiLine(true);
+      label->SetHorizontalAlignment(gfx::ALIGN_LEFT);
+      UpdateView(label);
+      RestartAutoCloseTimer();
+    }
   }
 
   // Overridden from TrayNotificationView:
   virtual void OnClickAction() OVERRIDE {
-    OpenSettings();
+    OpenSettings(login_status_);
   }
 
  private:
+  user::LoginStatus login_status_;
+
   DISALLOW_COPY_AND_ASSIGN(DisplayNotificationView);
 };
 
 TrayDisplay::TrayDisplay(SystemTray* system_tray)
     : SystemTrayItem(system_tray),
       default_(NULL),
-      notification_(NULL),
-      current_mode_(GetCurrentTrayDisplayMode()) {
+      notification_(NULL) {
+  current_message_ = GetDisplayMessageForNotification();
   Shell::GetInstance()->display_controller()->AddObserver(this);
 }
 
@@ -212,6 +245,45 @@ TrayDisplay::~TrayDisplay() {
   Shell::GetInstance()->display_controller()->RemoveObserver(this);
 }
 
+base::string16 TrayDisplay::GetDisplayMessageForNotification() {
+  DisplayManager* display_manager = GetDisplayManager();
+  DisplayInfoMap old_info;
+  old_info.swap(display_info_);
+  for (size_t i = 0; i < display_manager->GetNumDisplays(); ++i) {
+    int64 id = display_manager->GetDisplayAt(i)->id();
+    display_info_[id] = display_manager->GetDisplayInfo(id);
+  }
+
+  // Display is added or removed. Use the same message as the one in
+  // the system tray.
+  if (display_info_.size() != old_info.size())
+    return GetTrayDisplayMessage();
+
+  for (DisplayInfoMap::const_iterator iter = display_info_.begin();
+       iter != display_info_.end(); ++iter) {
+    DisplayInfoMap::const_iterator old_iter = old_info.find(iter->first);
+    // A display is removed and added at the same time. It won't happen
+    // in the actual environment, but falls back to the system tray's
+    // message just in case.
+    if (old_iter == old_info.end())
+      return GetTrayDisplayMessage();
+
+    if (iter->second.ui_scale() != old_iter->second.ui_scale()) {
+      return l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_RESOLUTION_CHANGED,
+          GetDisplayName(iter->first),
+          GetDisplaySize(iter->first));
+    }
+    if (iter->second.rotation() != old_iter->second.rotation()) {
+      return l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_ROTATED, GetDisplayName(iter->first));
+    }
+  }
+
+  // Found nothing special
+  return base::string16();
+}
+
 views::View* TrayDisplay::CreateDefaultView(user::LoginStatus status) {
   DCHECK(default_ == NULL);
   default_ = new DisplayView(status);
@@ -220,7 +292,7 @@ views::View* TrayDisplay::CreateDefaultView(user::LoginStatus status) {
 
 views::View* TrayDisplay::CreateNotificationView(user::LoginStatus status) {
   DCHECK(notification_ == NULL);
-  notification_ = new DisplayNotificationView(status, this);
+  notification_ = new DisplayNotificationView(status, this, current_message_);
   return notification_;
 }
 
@@ -237,14 +309,28 @@ bool TrayDisplay::ShouldShowLauncher() const {
 }
 
 void TrayDisplay::OnDisplayConfigurationChanged() {
-  TrayDisplayMode new_mode = GetCurrentTrayDisplayMode();
-  if (current_mode_ != new_mode && new_mode != TRAY_DISPLAY_SINGLE) {
-    if (notification_)
-      notification_->Update();
-    else
-      ShowNotificationView();
-  }
-  current_mode_ = new_mode;
+  if (display_notifications_disabled)
+    return;
+
+  // TODO(mukai): do not show the notification when the configuration changed
+  // due to the user operation on display settings page.
+  current_message_ = GetDisplayMessageForNotification();
+  if (notification_)
+    notification_->Update(current_message_);
+  else if (!current_message_.empty())
+    ShowNotificationView();
+}
+
+// static
+void TrayDisplay::SetDisplayNotificationsDisabledForTest(bool disabled) {
+  display_notifications_disabled = disabled;
+}
+
+base::string16 TrayDisplay::GetDefaultViewMessage() {
+  if (!default_ || !default_->visible())
+    return base::string16();
+
+  return static_cast<DisplayView*>(default_)->label()->text();
 }
 
 }  // namespace internal
diff --git a/ash/system/chromeos/tray_display.h b/ash/system/chromeos/tray_display.h
index 0265704..4c2faa73 100644
--- a/ash/system/chromeos/tray_display.h
+++ b/ash/system/chromeos/tray_display.h
@@ -5,33 +5,40 @@
 #ifndef ASH_SYSTEM_CHROMEOS_TRAY_DISPLAY_H_
 #define ASH_SYSTEM_CHROMEOS_TRAY_DISPLAY_H_
 
+#include <map>
+
+#include "ash/ash_export.h"
 #include "ash/display/display_controller.h"
+#include "ash/display/display_info.h"
 #include "ash/system/tray/system_tray_item.h"
+#include "base/strings/string16.h"
+#include "ui/views/view.h"
 
-namespace views {
-class View;
+namespace ash {
+namespace test {
+class AshTestBase;
 }
 
-namespace ash {
 namespace internal {
 
-enum TrayDisplayMode {
-  TRAY_DISPLAY_SINGLE,
-  TRAY_DISPLAY_EXTENDED,
-  TRAY_DISPLAY_MIRRORED,
-  TRAY_DISPLAY_DOCKED,
-};
-
-class DisplayView;
 class DisplayNotificationView;
 
-class TrayDisplay : public SystemTrayItem,
-                    public DisplayController::Observer {
+class ASH_EXPORT TrayDisplay : public SystemTrayItem,
+                               public DisplayController::Observer {
  public:
   explicit TrayDisplay(SystemTray* system_tray);
   virtual ~TrayDisplay();
 
  private:
+  friend class test::AshTestBase;
+  friend class TrayDisplayTest;
+
+  typedef std::map<int64, DisplayInfo> DisplayInfoMap;
+
+  // Checks the current display settings and determine what message should be
+  // shown for notification.
+  base::string16 GetDisplayMessageForNotification();
+
   // Overridden from SystemTrayItem.
   virtual views::View* CreateDefaultView(user::LoginStatus status) OVERRIDE;
   virtual views::View* CreateNotificationView(
@@ -43,9 +50,19 @@ class TrayDisplay : public SystemTrayItem,
   // Overridden from DisplayControllerObserver:
   virtual void OnDisplayConfigurationChanged() OVERRIDE;
 
-  DisplayView* default_;
+  // Call this with |diabled| = false when the test case wants to see the
+  // display notification.
+  static void SetDisplayNotificationsDisabledForTest(bool disabled);
+
+  // Test accessors.
+  base::string16 GetDefaultViewMessage();
+  views::View* default_view() { return default_; }
+  const string16& current_message() const { return current_message_; }
+
+  views::View* default_;
   DisplayNotificationView* notification_;
-  TrayDisplayMode current_mode_;
+  string16 current_message_;
+  DisplayInfoMap display_info_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayDisplay);
 };
diff --git a/ash/system/chromeos/tray_display_unittest.cc b/ash/system/chromeos/tray_display_unittest.cc
new file mode 100644
index 0000000..8c2ec5b
--- /dev/null
+++ b/ash/system/chromeos/tray_display_unittest.cc
@@ -0,0 +1,340 @@
+// Copyright 2013 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/system/chromeos/tray_display.h"
+
+#include "ash/display/display_manager.h"
+#include "ash/root_window_controller.h"
+#include "ash/screen_ash.h"
+#include "ash/shell.h"
+#include "ash/system/tray/system_tray.h"
+#include "ash/test/ash_test_base.h"
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
+#include "grit/ash_strings.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/gfx/display.h"
+#include "ui/views/controls/label.h"
+
+namespace ash {
+namespace internal {
+
+base::string16 GetTooltipText(const base::string16& line1,
+                              const base::string16& line2) {
+  return line1 + ASCIIToUTF16("\n") + line2;
+}
+
+base::string16 GetTooltipText1(const base::string16& line1) {
+  return GetTooltipText(line1, base::string16());
+}
+
+base::string16 GetTooltipText2(const base::string16& line2) {
+  return GetTooltipText(base::string16(), line2);
+}
+
+base::string16 GetFirstDisplayName() {
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  return UTF8ToUTF16(display_manager->GetDisplayNameForId(
+      display_manager->first_display_id()));
+}
+
+base::string16 GetSecondDisplayName() {
+  return UTF8ToUTF16(
+      Shell::GetInstance()->display_manager()->GetDisplayNameForId(
+          ScreenAsh::GetSecondaryDisplay().id()));
+}
+
+base::string16 GetMirroredDisplayName() {
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  return UTF8ToUTF16(display_manager->GetDisplayNameForId(
+      display_manager->mirrored_display().id()));
+}
+
+class TrayDisplayTest : public ash::test::AshTestBase {
+ public:
+  TrayDisplayTest();
+  virtual ~TrayDisplayTest();
+
+  virtual void SetUp() OVERRIDE;
+
+ protected:
+  SystemTray* tray() { return tray_; }
+
+  void CloseNotification();
+  bool IsDisplayVisibleInTray();
+  base::string16 GetTrayDisplayText();
+  base::string16 GetTrayDisplayTooltipText();
+  base::string16 GetDisplayNotificationText();
+
+ private:
+  // Weak reference, owned by Shell.
+  SystemTray* tray_;
+
+  // Weak reference, owned by |tray_|.
+  TrayDisplay* tray_display_;
+
+  DISALLOW_COPY_AND_ASSIGN(TrayDisplayTest);
+};
+
+TrayDisplayTest::TrayDisplayTest() : tray_(NULL), tray_display_(NULL) {
+}
+
+TrayDisplayTest::~TrayDisplayTest() {
+}
+
+void TrayDisplayTest::SetUp() {
+  ash::test::AshTestBase::SetUp();
+  tray_ = Shell::GetPrimaryRootWindowController()->GetSystemTray();
+  tray_display_ = new TrayDisplay(tray_);
+  tray_->AddTrayItem(tray_display_);
+  TrayDisplay::SetDisplayNotificationsDisabledForTest(false);
+}
+
+void TrayDisplayTest::CloseNotification() {
+  tray()->CloseNotificationBubbleForTest();
+  tray_display_->HideNotificationView();
+  RunAllPendingInMessageLoop();
+}
+
+bool TrayDisplayTest::IsDisplayVisibleInTray() {
+  return tray_display_->default_view() &&
+      tray_display_->default_view()->visible();
+}
+
+base::string16 TrayDisplayTest::GetTrayDisplayText() {
+  return tray_display_->GetDefaultViewMessage();
+}
+
+base::string16 TrayDisplayTest::GetTrayDisplayTooltipText() {
+  if (!tray_display_->default_view())
+    return base::string16();
+
+  base::string16 tooltip;
+  if (!tray_display_->default_view()->GetTooltipText(gfx::Point(), &tooltip))
+    return base::string16();
+  return tooltip;
+}
+
+base::string16 TrayDisplayTest::GetDisplayNotificationText() {
+  return tray_display_->current_message();
+}
+
+TEST_F(TrayDisplayTest, NoInternalDisplay) {
+  UpdateDisplay("400x400");
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_FALSE(IsDisplayVisibleInTray());
+
+  UpdateDisplay("400x400,200x200");
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+  base::string16 expected = l10n_util::GetStringUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED_NO_INTERNAL);
+  EXPECT_EQ(expected, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText1(expected), GetTrayDisplayTooltipText());
+
+  // mirroring
+  Shell::GetInstance()->display_manager()->SetSoftwareMirroring(true);
+  UpdateDisplay("400x400,200x200");
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+  expected = l10n_util::GetStringUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING_NO_INTERNAL);
+  EXPECT_EQ(expected, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText1(expected), GetTrayDisplayTooltipText());
+}
+
+TEST_F(TrayDisplayTest, InternalDisplay) {
+  UpdateDisplay("400x400");
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  gfx::Display::SetInternalDisplayId(display_manager->first_display_id());
+
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_FALSE(IsDisplayVisibleInTray());
+
+  // Extended
+  UpdateDisplay("400x400,200x200");
+  string16 expected = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED, GetSecondDisplayName());
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+  EXPECT_EQ(expected, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText1(expected), GetTrayDisplayTooltipText());
+
+  // Mirroring
+  display_manager->SetSoftwareMirroring(true);
+  UpdateDisplay("400x400,200x200");
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+
+  expected = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING, GetMirroredDisplayName());
+  EXPECT_EQ(expected, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText1(expected), GetTrayDisplayTooltipText());
+
+  // TODO(mukai): add test case for docked mode here.
+}
+
+TEST_F(TrayDisplayTest, InternalDisplayResized) {
+  UpdateDisplay("400x400@1.5");
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  gfx::Display::SetInternalDisplayId(display_manager->first_display_id());
+
+  // Shows the tray_display even though there's a single-display.
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+  base::string16 internal_info = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_SINGLE_DISPLAY,
+      GetFirstDisplayName(),
+      UTF8ToUTF16("600x600"));
+  EXPECT_EQ(internal_info, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText2(internal_info), GetTrayDisplayTooltipText());
+
+  // Extended
+  UpdateDisplay("400x400@1.5,200x200");
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+  base::string16 expected = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED, GetSecondDisplayName());
+  EXPECT_EQ(expected, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText(expected, internal_info),
+            GetTrayDisplayTooltipText());
+
+  // Mirroring
+  display_manager->SetSoftwareMirroring(true);
+  UpdateDisplay("400x400@1.5,200x200");
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+  expected = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING, GetMirroredDisplayName());
+  EXPECT_EQ(expected, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText(expected, internal_info),
+            GetTrayDisplayTooltipText());
+}
+
+TEST_F(TrayDisplayTest, ExternalDisplayResized) {
+  UpdateDisplay("400x400");
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  gfx::Display::SetInternalDisplayId(display_manager->first_display_id());
+
+  // Shows the tray_display even though there's a single-display.
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_FALSE(IsDisplayVisibleInTray());
+
+  // Extended
+  UpdateDisplay("400x400,200x200@1.5");
+  const gfx::Display& secondary_display = ScreenAsh::GetSecondaryDisplay();
+  base::string16 secondary_annotation = UTF8ToUTF16(
+      " (" + secondary_display.size().ToString() + ")");
+
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+  base::string16 expected = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED,
+      GetSecondDisplayName() + secondary_annotation);
+  EXPECT_EQ(expected, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText1(expected), GetTrayDisplayTooltipText());
+
+  // Mirroring: in mirroring, it's not possible to lookup the DisplayInfo.
+  display_manager->SetSoftwareMirroring(true);
+  UpdateDisplay("400x400,200x200@1.5");
+  tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
+  EXPECT_TRUE(IsDisplayVisibleInTray());
+  expected = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING, GetMirroredDisplayName());
+  EXPECT_EQ(expected, GetTrayDisplayText());
+  EXPECT_EQ(GetTooltipText1(expected), GetTrayDisplayTooltipText());
+}
+
+TEST_F(TrayDisplayTest, DisplayNotifications) {
+  UpdateDisplay("400x400");
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  gfx::Display::SetInternalDisplayId(display_manager->first_display_id());
+  EXPECT_FALSE(tray()->HasNotificationBubble());
+
+  // rotation.
+  UpdateDisplay("400x400/r");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  base::string16 rotation_message = l10n_util::GetStringFUTF16(
+      IDS_ASH_STATUS_TRAY_DISPLAY_ROTATED, GetFirstDisplayName());
+  EXPECT_EQ(rotation_message, GetDisplayNotificationText());
+
+  CloseNotification();
+  UpdateDisplay("400x400");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  EXPECT_EQ(rotation_message, GetDisplayNotificationText());
+
+  // UI-scale
+  CloseNotification();
+  UpdateDisplay("400x400@1.5");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  EXPECT_EQ(
+      l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_RESOLUTION_CHANGED,
+          GetFirstDisplayName(), UTF8ToUTF16("600x600")),
+      GetDisplayNotificationText());
+
+  // UI-scale to 1.0
+  CloseNotification();
+  UpdateDisplay("400x400");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  EXPECT_EQ(
+      l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_RESOLUTION_CHANGED,
+          GetFirstDisplayName(), UTF8ToUTF16("400x400")),
+      GetDisplayNotificationText());
+
+  // No-update
+  CloseNotification();
+  UpdateDisplay("400x400");
+  EXPECT_FALSE(tray()->HasNotificationBubble());
+
+  // Extended.
+  CloseNotification();
+  UpdateDisplay("400x400,200x200");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  EXPECT_EQ(
+      l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED, GetSecondDisplayName()),
+      GetDisplayNotificationText());
+
+  // Mirroring.
+  CloseNotification();
+  display_manager->SetSoftwareMirroring(true);
+  UpdateDisplay("400x400,200x200");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  EXPECT_EQ(
+      l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_MIRRORING, GetMirroredDisplayName()),
+      GetDisplayNotificationText());
+
+  // Back to extended.
+  CloseNotification();
+  display_manager->SetSoftwareMirroring(false);
+  UpdateDisplay("400x400,200x200");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  EXPECT_EQ(
+      l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_EXTENDED, GetSecondDisplayName()),
+      GetDisplayNotificationText());
+
+  // Resize the first display.
+  UpdateDisplay("400x400@1.5,200x200");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  EXPECT_EQ(
+      l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_RESOLUTION_CHANGED,
+          GetFirstDisplayName(), UTF8ToUTF16("600x600")),
+      GetDisplayNotificationText());
+
+  // rotate the second.
+  UpdateDisplay("400x400@1.5,200x200/r");
+  EXPECT_TRUE(tray()->HasNotificationBubble());
+  EXPECT_EQ(
+      l10n_util::GetStringFUTF16(
+          IDS_ASH_STATUS_TRAY_DISPLAY_ROTATED, GetSecondDisplayName()),
+      GetDisplayNotificationText());
+}
+
+}  // namespace internal
+}  // namespace ash
diff --git a/ash/test/ash_test_base.cc b/ash/test/ash_test_base.cc
index 7c03586..079f135 100644
--- a/ash/test/ash_test_base.cc
+++ b/ash/test/ash_test_base.cc
@@ -30,6 +30,10 @@
 #include "ui/gfx/point.h"
 #include "ui/gfx/screen.h"
 
+#if defined(OS_CHROMEOS)
+#include "ash/system/chromeos/tray_display.h"
+#endif
+
 #if defined(OS_WIN)
 #include "ash/test/test_metro_viewer_process_host.h"
 #include "base/test/test_process_killer_win.h"
@@ -114,6 +118,14 @@ void AshTestBase::SetUp() {
   Shell::GetPrimaryRootWindow()->MoveCursorTo(gfx::Point(-1000, -1000));
   ash::Shell::GetInstance()->cursor_manager()->EnableMouseEvents();
 
+#if defined(OS_CHROMEOS)
+  // We do not want to see the notification for display configuration change,
+  // since it may trap mouse events unexpectedly.
+  // TODO(mukai): remove this code when the display notification code is moved
+  // to the message center.
+  internal::TrayDisplay::SetDisplayNotificationsDisabledForTest(true);
+#endif
+
 #if defined(OS_WIN)
   if (base::win::GetVersion() >= base::win::VERSION_WIN8 &&
       !CommandLine::ForCurrentProcess()->HasSwitch(