Implement chromeos SystemNotification on Aura by introducing BalloonCollectionImplAura.

BUG=98331
TEST=Test system notifications (failed network connect, low battery) on ChromeOS Aura.


Review URL: http://codereview.chromium.org/9187043

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@117984 0039d316-1c4b-4281-b951-d872f2087c98

24 files changed, 493 insertions, 202 deletions

diff --git a/chrome/browser/chromeos/cros_stubs_aura.cc b/chrome/browser/chromeos/cros_stubs_aura.cc
deleted file mode 100644
index d4039d6..0000000
--- a/chrome/browser/chromeos/cros_stubs_aura.cc
+++ /dev/null
@@ -1,77 +0,0 @@
-// Copyright (c) 2011 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/notifications/system_notification.h"
-#include "chrome/browser/notifications/balloon_collection.h"
-
-namespace chromeos {
-
-////////////////////////////////////////////////////////////////////////////////
-// SystemNotification
-
-void SystemNotification::Init(int icon_resource_id) {
-  NOTIMPLEMENTED();
-}
-
-SystemNotification::SystemNotification(Profile* profile,
-                                       NotificationDelegate* delegate,
-                                       int icon_resource_id,
-                                       const string16& title)
-    : profile_(profile),
-      collection_(NULL),
-      delegate_(delegate),
-      title_(title),
-      visible_(false),
-      urgent_(false) {
-  NOTIMPLEMENTED();
-}
-
-SystemNotification::SystemNotification(Profile* profile,
-                                       const std::string& id,
-                                       int icon_resource_id,
-                                       const string16& title)
-    : profile_(profile),
-      collection_(NULL),
-      delegate_(new Delegate(id)),
-      title_(title),
-      visible_(false),
-      urgent_(false) {
-  NOTIMPLEMENTED();
-}
-
-SystemNotification::~SystemNotification() {
-}
-
-void SystemNotification::Show(const string16& message,
-                              bool urgent,
-                              bool sticky) {
-  NOTIMPLEMENTED() << " " << message;
-}
-
-void SystemNotification::Show(const string16& message,
-                              const string16& link,
-                              const MessageCallback& callback,
-                              bool urgent,
-                              bool sticky) {
-  NOTIMPLEMENTED();
-}
-
-void SystemNotification::Hide() {
-  NOTIMPLEMENTED();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// SystemNotification::Delegate
-
-SystemNotification::Delegate::Delegate(const std::string& id)
-    : id_(id) {
-  NOTIMPLEMENTED();
-}
-
-std::string SystemNotification::Delegate::id() const {
-  NOTIMPLEMENTED();
-  return id_;
-}
-
-}  // namespace chromeos
diff --git a/chrome/browser/chromeos/extensions/file_browser_notifications.cc b/chrome/browser/chromeos/extensions/file_browser_notifications.cc
index 1a5ed13..38ea6ad 100644
--- a/chrome/browser/chromeos/extensions/file_browser_notifications.cc
+++ b/chrome/browser/chromeos/extensions/file_browser_notifications.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -307,7 +307,7 @@ const string16& FileBrowserNotifications::GetLinkText() {
   return link_text_;
 }
 
-chromeos::MessageCallback FileBrowserNotifications::GetLinkCallback() {
+chromeos::BalloonViewHost::MessageCallback
+FileBrowserNotifications::GetLinkCallback() {
   return base::Bind(&FileBrowserNotifications::OnLinkClicked, AsWeakPtr());
 }
-
diff --git a/chrome/browser/chromeos/extensions/file_browser_notifications.h b/chrome/browser/chromeos/extensions/file_browser_notifications.h
index 889c437..96d943e 100644
--- a/chrome/browser/chromeos/extensions/file_browser_notifications.h
+++ b/chrome/browser/chromeos/extensions/file_browser_notifications.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -110,7 +110,7 @@ class FileBrowserNotifications
   void OnLinkClicked(const base::ListValue* arg);
   bool HasMoreInfoLink(NotificationType type);
   const string16& GetLinkText();
-  chromeos::MessageCallback GetLinkCallback();
+  chromeos::BalloonViewHost::MessageCallback GetLinkCallback();
 
   string16 link_text_;
   NotificationMap notifications_;
@@ -121,4 +121,3 @@ class FileBrowserNotifications
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_BROWSER_NOTIFICATIONS_H_
-
diff --git a/chrome/browser/chromeos/notifications/balloon_collection_impl.cc b/chrome/browser/chromeos/notifications/balloon_collection_impl.cc
index eb8d8aa..deba6fa 100644
--- a/chrome/browser/chromeos/notifications/balloon_collection_impl.cc
+++ b/chrome/browser/chromeos/notifications/balloon_collection_impl.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -40,7 +40,7 @@ BalloonCollectionImpl::~BalloonCollectionImpl() {
 void BalloonCollectionImpl::Add(const Notification& notification,
                                 Profile* profile) {
   Balloon* new_balloon = MakeBalloon(notification, profile);
-  base_.Add(new_balloon);
+  base_.Add(new_balloon, false);
   new_balloon->Show();
   notification_ui_->Add(new_balloon);
 
@@ -56,7 +56,7 @@ void BalloonCollectionImpl::Add(const Notification& notification,
 bool BalloonCollectionImpl::AddWebUIMessageCallback(
     const Notification& notification,
     const std::string& message,
-    const MessageCallback& callback) {
+    const BalloonViewHost::MessageCallback& callback) {
   Balloon* balloon = FindBalloon(notification);
   if (!balloon)
     return false;
@@ -66,16 +66,16 @@ bool BalloonCollectionImpl::AddWebUIMessageCallback(
   return host->AddWebUIMessageCallback(message, callback);
 }
 
+// Called from SystemNotification::Show for system notifications.
 void BalloonCollectionImpl::AddSystemNotification(
     const Notification& notification,
     Profile* profile,
-    bool sticky,
-    bool control) {
-
+    bool sticky) {
   Balloon* new_balloon = new Balloon(notification, profile, this);
   new_balloon->set_view(
-      new chromeos::BalloonViewImpl(sticky, control, true));
-  base_.Add(new_balloon);
+      new chromeos::BalloonViewImpl(
+          sticky, false /*no controls*/, true /*enable webui*/));
+  base_.Add(new_balloon, false);
   new_balloon->Show();
   notification_ui_->Add(new_balloon);
 
@@ -167,10 +167,12 @@ void BalloonCollectionImpl::Shutdown() {
   notification_ui_.reset();
 }
 
+// Called from BalloonCollectionImpl::Add for non system notifications.
 Balloon* BalloonCollectionImpl::MakeBalloon(const Notification& notification,
                                             Profile* profile) {
   Balloon* new_balloon = new Balloon(notification, profile, this);
-  new_balloon->set_view(new chromeos::BalloonViewImpl(false, true, false));
+  new_balloon->set_view(new chromeos::BalloonViewImpl(
+      false /*not sticky*/, true /*has controls*/, false /*no web ui*/));
   return new_balloon;
 }
 
diff --git a/chrome/browser/chromeos/notifications/balloon_collection_impl.h b/chrome/browser/chromeos/notifications/balloon_collection_impl.h
index 94e8c2c..aacc238 100644
--- a/chrome/browser/chromeos/notifications/balloon_collection_impl.h
+++ b/chrome/browser/chromeos/notifications/balloon_collection_impl.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -81,16 +81,17 @@ class BalloonCollectionImpl : public BalloonCollection,
   // there is no notification that matches NotificationDelegate::id(),
   // or a callback for given message already exists. The callback
   // object is owned and deleted by callee.
-  bool AddWebUIMessageCallback(const Notification& notification,
-                               const std::string& message,
-                               const MessageCallback& callback);
+  bool AddWebUIMessageCallback(
+      const Notification& notification,
+      const std::string& message,
+      const BalloonViewHost::MessageCallback& callback);
 
   // Adds new system notification.
   // |sticky| is used to indicate that the notification
-  // is sticky and cannot be dismissed by a user. |controls| turns on/off
-  // info label and option/dismiss buttons.
+  // is sticky and cannot be dismissed by a user.
   void AddSystemNotification(const Notification& notification,
-                             Profile* profile, bool sticky, bool controls);
+                             Profile* profile,
+                             bool sticky);
 
   // Updates the notification's content. It uses
   // NotificationDelegate::id() to check the equality of notifications.
@@ -104,6 +105,10 @@ class BalloonCollectionImpl : public BalloonCollection,
   // the updated notification is visible.
   bool UpdateAndShowNotification(const Notification& notification);
 
+  // base_ is embedded, so this is a simple accessor for the number of
+  // balloons in the collection.
+  int count() const { return base_.count(); }
+
   // Injects notification ui. Used to inject a mock implementation in tests.
   void set_notification_ui(NotificationUI* ui) {
     notification_ui_.reset(ui);
diff --git a/chrome/browser/chromeos/notifications/balloon_collection_impl_aura.cc b/chrome/browser/chromeos/notifications/balloon_collection_impl_aura.cc
new file mode 100644
index 0000000..b4a402c
--- /dev/null
+++ b/chrome/browser/chromeos/notifications/balloon_collection_impl_aura.cc
@@ -0,0 +1,72 @@
+// 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 "chrome/browser/chromeos/notifications/balloon_collection_impl_aura.h"
+
+#include "chrome/browser/notifications/balloon.h"
+#include "chrome/browser/notifications/notification.h"
+#include "chrome/browser/ui/views/notifications/balloon_view.h"
+#include "chrome/browser/ui/views/notifications/balloon_view_host.h"
+
+namespace chromeos {
+
+bool BalloonCollectionImplAura::AddWebUIMessageCallback(
+    const Notification& notification,
+    const std::string& message,
+    const BalloonViewHost::MessageCallback& callback) {
+  Balloon* balloon = base().FindBalloon(notification);
+  if (!balloon)
+    return false;
+
+  BalloonViewHost* host =
+      static_cast<chromeos::BalloonViewHost*>(balloon->view()->GetHost());
+  return host->AddWebUIMessageCallback(message, callback);
+}
+
+void BalloonCollectionImplAura::AddSystemNotification(
+    const Notification& notification,
+    Profile* profile,
+    bool sticky) {
+  system_notifications_.insert(notification.notification_id());
+
+  // Add balloons to the front of the stack. This ensures that system
+  // notifications will always be displayed. NOTE: This has the side effect
+  // that system notifications are displayed in inverse order, with the most
+  // recent notification always at the front of the list.
+  AddImpl(notification, profile, true /* add to front*/);
+}
+
+bool BalloonCollectionImplAura::UpdateNotification(
+    const Notification& notification) {
+  Balloon* balloon = base().FindBalloon(notification);
+  if (!balloon)
+    return false;
+  balloon->Update(notification);
+  return true;
+}
+
+bool BalloonCollectionImplAura::UpdateAndShowNotification(
+    const Notification& notification) {
+  return UpdateNotification(notification);
+}
+
+Balloon* BalloonCollectionImplAura::MakeBalloon(
+    const Notification& notification, Profile* profile) {
+  Balloon* balloon = new Balloon(notification, profile, this);
+  ::BalloonViewImpl* balloon_view = new ::BalloonViewImpl(this);
+  if (system_notifications_.find(notification.notification_id()) !=
+      system_notifications_.end())
+    balloon_view->set_enable_web_ui(true);
+  balloon->set_view(balloon_view);
+  gfx::Size size(layout().min_balloon_width(), layout().min_balloon_height());
+  balloon->set_content_size(size);
+  return balloon;
+}
+
+}  // namespace chromeos
+
+// static
+BalloonCollection* BalloonCollection::Create() {
+  return new chromeos::BalloonCollectionImplAura();
+}
diff --git a/chrome/browser/chromeos/notifications/balloon_collection_impl_aura.h b/chrome/browser/chromeos/notifications/balloon_collection_impl_aura.h
new file mode 100644
index 0000000..65d76a1
--- /dev/null
+++ b/chrome/browser/chromeos/notifications/balloon_collection_impl_aura.h
@@ -0,0 +1,65 @@
+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_NOTIFICATIONS_BALLOON_COLLECTION_IMPL_AURA_H_
+#define CHROME_BROWSER_CHROMEOS_NOTIFICATIONS_BALLOON_COLLECTION_IMPL_AURA_H_
+#pragma once
+
+#include <set>
+
+#include "chrome/browser/chromeos/notifications/balloon_view_host.h"  // MessageCallback
+#include "chrome/browser/notifications/balloon_collection_impl.h"
+
+namespace chromeos {
+
+// Wrapper on top of ::BalloonCollectionImpl to provide an interface for
+// chromeos::SystemNotification.
+class BalloonCollectionImplAura : public ::BalloonCollectionImpl {
+ public:
+  BalloonCollectionImplAura() {}
+
+  // Adds a callback for WebUI message. Returns true if the callback
+  // is succssfully registered, or false otherwise. It fails to add if
+  // there is no notification that matches NotificationDelegate::id(),
+  // or a callback for given message already exists. The callback
+  // object is owned and deleted by callee.
+  bool AddWebUIMessageCallback(
+      const Notification& notification,
+      const std::string& message,
+      const BalloonViewHost::MessageCallback& callback);
+
+  // Adds a new system notification.
+  // |sticky| is ignored in the Aura implementation; desktop notifications
+  // are always sticky (i.e. they need to be dismissed explicitly).
+  void AddSystemNotification(const Notification& notification,
+                             Profile* profile,
+                             bool sticky);
+
+  // Updates the notification's content. It uses
+  // NotificationDelegate::id() to check the equality of notifications.
+  // Returns true if the notification has been updated. False if
+  // no corresponding notification is found. This will not change the
+  // visibility of the notification.
+  bool UpdateNotification(const Notification& notification);
+
+  // On Aura this behaves the same as UpdateNotification.
+  bool UpdateAndShowNotification(const Notification& notification);
+
+ protected:
+  // Creates a new balloon. Overridable by unit tests.  The caller is
+  // responsible for freeing the pointer returned.
+  virtual Balloon* MakeBalloon(const Notification& notification,
+                               Profile* profile);
+
+ private:
+  // Set of unique ids associated with system notifications, used by
+  // MakeBalloon to determine whether or not to enable Web UI.
+  std::set<std::string> system_notifications_;
+
+  DISALLOW_COPY_AND_ASSIGN(BalloonCollectionImplAura);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_NOTIFICATIONS_BALLOON_COLLECTION_IMPL_AURA_H_
diff --git a/chrome/browser/chromeos/notifications/balloon_view_host.h b/chrome/browser/chromeos/notifications/balloon_view_host.h
index 19fca89..3571df6 100644
--- a/chrome/browser/chromeos/notifications/balloon_view_host.h
+++ b/chrome/browser/chromeos/notifications/balloon_view_host.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -23,10 +23,10 @@ class ListValue;
 
 namespace chromeos {
 
-typedef base::Callback<void(const base::ListValue*)> MessageCallback;
-
 class BalloonViewHost : public ::BalloonViewHost {
  public:
+  typedef base::Callback<void(const base::ListValue*)> MessageCallback;
+
   explicit BalloonViewHost(Balloon* balloon);
   virtual ~BalloonViewHost();
 
diff --git a/chrome/browser/chromeos/notifications/desktop_notifications_unittest.cc b/chrome/browser/chromeos/notifications/desktop_notifications_unittest.cc
index 90625bb..bd2e9e6 100644
--- a/chrome/browser/chromeos/notifications/desktop_notifications_unittest.cc
+++ b/chrome/browser/chromeos/notifications/desktop_notifications_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -10,6 +10,19 @@
 #include "chrome/browser/prefs/pref_service.h"
 #include "content/public/common/show_desktop_notification_params.h"
 
+#if defined(USE_AURA)
+#include "chrome/browser/chromeos/notifications/balloon_collection_impl_aura.h"
+#include "ui/aura/root_window.h"
+#else
+#include "chrome/browser/chromeos/notifications/balloon_collection_impl.h"
+#endif
+
+#if defined(USE_AURA)
+typedef class chromeos::BalloonCollectionImplAura BalloonCollectionImplType;
+#else
+typedef class chromeos::BalloonCollectionImpl BalloonCollectionImplType;
+#endif
+
 using content::BrowserThread;
 
 namespace chromeos {
@@ -17,7 +30,10 @@ namespace chromeos {
 // static
 std::string DesktopNotificationsTest::log_output_;
 
-class MockNotificationUI : public BalloonCollectionImpl::NotificationUI {
+class BalloonViewImpl;
+
+#if !defined(USE_AURA)
+class MockNotificationUI : public BalloonCollectionImplType::NotificationUI {
  public:
   virtual void Add(Balloon* balloon) {}
   virtual bool Update(Balloon* balloon) { return false; }
@@ -27,31 +43,54 @@ class MockNotificationUI : public BalloonCollectionImpl::NotificationUI {
                                   const gfx::Size& size) {}
   virtual void SetActiveView(BalloonViewImpl* view) {}
 };
+#endif
 
-MockBalloonCollection::MockBalloonCollection() {
-  set_notification_ui(new MockNotificationUI());
-}
+// Test version of the balloon collection which counts the number
+// of notifications that are added to it.
+class MockBalloonCollection : public BalloonCollectionImplType {
+ public:
+  MockBalloonCollection() {
+#if !defined(USE_AURA)
+    set_notification_ui(new MockNotificationUI());
+#endif
+  }
+  virtual ~MockBalloonCollection() {};
 
-MockBalloonCollection::~MockBalloonCollection() {}
+  // BalloonCollectionImplType overrides
+  virtual void Add(const Notification& notification, Profile* profile) OVERRIDE;
+  virtual Balloon* MakeBalloon(const Notification& notification,
+                               Profile* profile) OVERRIDE;
+  virtual void OnBalloonClosed(Balloon* source) OVERRIDE;
+
+  // Number of balloons being shown.
+  std::set<Balloon*>& balloons() { return balloons_; }
+  int count() const { return balloons_.size(); }
+
+ private:
+  std::set<Balloon*> balloons_;
+};
 
 void MockBalloonCollection::Add(const Notification& notification,
                                 Profile* profile) {
   // Swap in a logging proxy for the purpose of logging calls that
   // would be made into javascript, then pass this down to the
   // balloon collection.
+  typedef LoggingNotificationDelegate<DesktopNotificationsTest>
+      LoggingNotificationProxy;
   Notification test_notification(
       notification.origin_url(),
       notification.content_url(),
       notification.display_source(),
       notification.replace_id(),
       new LoggingNotificationProxy(notification.notification_id()));
-  BalloonCollectionImpl::Add(test_notification, profile);
+  BalloonCollectionImplType::Add(test_notification, profile);
 }
 
 Balloon* MockBalloonCollection::MakeBalloon(const Notification& notification,
                                             Profile* profile) {
   // Start with a normal balloon but mock out the view.
-  Balloon* balloon = BalloonCollectionImpl::MakeBalloon(notification, profile);
+  Balloon* balloon =
+      BalloonCollectionImplType::MakeBalloon(notification, profile);
   balloon->set_view(new MockBalloonView(balloon));
   balloons_.insert(balloon);
   return balloon;
@@ -59,19 +98,10 @@ Balloon* MockBalloonCollection::MakeBalloon(const Notification& notification,
 
 void MockBalloonCollection::OnBalloonClosed(Balloon* source) {
   balloons_.erase(source);
-  BalloonCollectionImpl::OnBalloonClosed(source);
+  BalloonCollectionImplType::OnBalloonClosed(source);
 }
 
-int MockBalloonCollection::UppermostVerticalPosition() {
-  int min = 0;
-  std::set<Balloon*>::iterator iter;
-  for (iter = balloons_.begin(); iter != balloons_.end(); ++iter) {
-    int pos = (*iter)->GetPosition().y();
-    if (iter == balloons_.begin() || pos < min)
-      min = pos;
-  }
-  return min;
-}
+// DesktopNotificationsTest
 
 DesktopNotificationsTest::DesktopNotificationsTest()
     : ui_thread_(BrowserThread::UI, &message_loop_) {
@@ -81,6 +111,10 @@ DesktopNotificationsTest::~DesktopNotificationsTest() {
 }
 
 void DesktopNotificationsTest::SetUp() {
+#if defined(USE_AURA)
+  // Make sure a root window has been instantiated.
+  aura::RootWindow::GetInstance();
+#endif
   browser::RegisterLocalState(&local_state_);
   profile_.reset(new TestingProfile());
   balloon_collection_ = new MockBalloonCollection();
@@ -195,7 +229,13 @@ TEST_F(DesktopNotificationsTest, TestManyNotifications) {
   int route_id = 0;
 
   // Request lots of identical notifications.
+#if defined(USE_AURA)
+  // Aura is using the non-chromeos notification system which has a limit
+  // of 4 visible toasts.
+  const int kLotsOfToasts = 4;
+#else
   const int kLotsOfToasts = 20;
+#endif
   for (int id = 1; id <= kLotsOfToasts; ++id) {
     SCOPED_TRACE(base::StringPrintf("Creation loop: id=%d", id));
     content::ShowDesktopNotificationHostMsgParams params =
diff --git a/chrome/browser/chromeos/notifications/desktop_notifications_unittest.h b/chrome/browser/chromeos/notifications/desktop_notifications_unittest.h
index 69c4464..e63d408 100644
--- a/chrome/browser/chromeos/notifications/desktop_notifications_unittest.h
+++ b/chrome/browser/chromeos/notifications/desktop_notifications_unittest.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -13,7 +13,6 @@
 #include "base/message_loop.h"
 #include "base/string_util.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
-#include "chrome/browser/chromeos/notifications/balloon_collection_impl.h"
 #include "chrome/browser/notifications/balloon.h"
 #include "chrome/browser/notifications/desktop_notification_service.h"
 #include "chrome/browser/notifications/notification.h"
@@ -32,33 +31,7 @@ struct ShowDesktopNotificationHostMsgParams;
 namespace chromeos {
 
 class DesktopNotificationsTest;
-typedef LoggingNotificationDelegate<DesktopNotificationsTest>
-    LoggingNotificationProxy;
-
-// Test version of the balloon collection which counts the number
-// of notifications that are added to it.
-class MockBalloonCollection : public BalloonCollectionImpl {
- public:
-  MockBalloonCollection();
-  virtual ~MockBalloonCollection();
-
-  // BalloonCollectionImpl overrides
-  virtual void Add(const Notification& notification,
-                   Profile* profile) OVERRIDE;
-  virtual Balloon* MakeBalloon(const Notification& notification,
-                               Profile* profile) OVERRIDE;
-  virtual void OnBalloonClosed(Balloon* source) OVERRIDE;
-
-  // Number of balloons being shown.
-  std::set<Balloon*>& balloons() { return balloons_; }
-  int count() const { return balloons_.size(); }
-
-  // Returns the highest y-coordinate of all the balloons in the collection.
-  int UppermostVerticalPosition();
-
- private:
-  std::set<Balloon*> balloons_;
-};
+class MockBalloonCollection;
 
 class DesktopNotificationsTest : public testing::Test {
  public:
diff --git a/chrome/browser/chromeos/notifications/notification_browsertest.cc b/chrome/browser/chromeos/notifications/notification_browsertest.cc
index 08124ee..1d2a417 100644
--- a/chrome/browser/chromeos/notifications/notification_browsertest.cc
+++ b/chrome/browser/chromeos/notifications/notification_browsertest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -226,7 +226,7 @@ IN_PROC_BROWSER_TEST_F(NotificationTest, TestSystemNotification) {
   NotificationPanelTester* tester = panel->GetTester();
 
   Notification notify = NewMockNotification(delegate.get());
-  collection->AddSystemNotification(notify, browser()->profile(), true, false);
+  collection->AddSystemNotification(notify, browser()->profile(), true);
 
   EXPECT_EQ(1, tester->GetNewNotificationCount());
   EXPECT_EQ(1, tester->GetStickyNotificationCount());
@@ -331,7 +331,7 @@ IN_PROC_BROWSER_TEST_F(NotificationTest, TestStateTransition2) {
 
   // The panel must be expanded again when a new system notification is added.
   collection->AddSystemNotification(
-      NewMockNotification("3"), browser()->profile(), true, false);
+      NewMockNotification("3"), browser()->profile(), true);
   EXPECT_EQ(3, tester->GetNotificationCount());
   EXPECT_EQ(NotificationPanel::STICKY_AND_NEW, tester->state());
   WaitForPanelState(tester, PanelController::EXPANDED);
@@ -433,7 +433,7 @@ IN_PROC_BROWSER_TEST_F(NotificationTest, DISABLED_TestScrollBalloonToVisible) {
       SCOPED_TRACE(base::StringPrintf("new system %d", i));
       std::string id = base::StringPrintf("s%d", i);
       collection->AddSystemNotification(
-          NewMockNotification(id), browser()->profile(), true, false);
+          NewMockNotification(id), browser()->profile(), true);
       BalloonViewImpl* view =
           tester->GetBalloonView(collection, NewMockNotification(id));
       WaitForVisible(view);
@@ -493,7 +493,7 @@ IN_PROC_BROWSER_TEST_F(NotificationTest, FLAKY_TestActivateDeactivate) {
 
   collection->Add(NewMockNotification("1"), profile);
   collection->AddSystemNotification(
-      NewMockNotification("2"), profile, true, false);
+      NewMockNotification("2"), profile, true);
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_EQ(NotificationPanel::STICKY_AND_NEW, tester->state());
   BalloonViewImpl* view1 =
@@ -526,7 +526,7 @@ IN_PROC_BROWSER_TEST_F(NotificationTest, TestCloseDismissAllNonSticky) {
 
   collection->Add(NewMockNotification("1"), profile);
   collection->AddSystemNotification(
-      NewMockNotification("2"), profile, true, false);
+      NewMockNotification("2"), profile, true);
   collection->Add(NewMockNotification("3"), profile);
 
   ui_test_utils::RunAllPendingInMessageLoop();
@@ -546,7 +546,7 @@ IN_PROC_BROWSER_TEST_F(NotificationTest, TestAddWebUIMessageCallback) {
   Profile* profile = browser()->profile();
 
   collection->AddSystemNotification(
-      NewMockNotification("1"), profile, false, false);
+      NewMockNotification("1"), profile, false);
 
   EXPECT_TRUE(collection->AddWebUIMessageCallback(
       NewMockNotification("1"),
@@ -582,7 +582,6 @@ IN_PROC_BROWSER_TEST_F(NotificationTest, TestWebUIMessageCallback) {
       Notification(GURL(), content_url, string16(), string16(),
                    new MockNotificationDelegate("1")),
       profile,
-      false,
       false);
   EXPECT_TRUE(collection->AddWebUIMessageCallback(
       NewMockNotification("1"),
diff --git a/chrome/browser/chromeos/notifications/system_notification.cc b/chrome/browser/chromeos/notifications/system_notification.cc
index 5196fa8..8127402 100644
--- a/chrome/browser/chromeos/notifications/system_notification.cc
+++ b/chrome/browser/chromeos/notifications/system_notification.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -6,17 +6,22 @@
 
 #include "base/callback.h"
 #include "chrome/browser/browser_process.h"
-#include "chrome/browser/chromeos/notifications/balloon_collection_impl.h"
 #include "chrome/browser/chromeos/notifications/system_notification_factory.h"
 #include "chrome/browser/notifications/notification.h"
 #include "chrome/browser/notifications/notification_ui_manager.h"
 #include "chrome/browser/ui/webui/web_ui_util.h"
 
+#if defined(USE_AURA)
+#include "chrome/browser/chromeos/notifications/balloon_collection_impl_aura.h"
+#else
+#include "chrome/browser/chromeos/notifications/balloon_collection_impl.h"
+#endif
+
 namespace chromeos {
 
 void SystemNotification::Init(int icon_resource_id) {
-  collection_ = static_cast<BalloonCollectionImpl*>(
-       g_browser_process->notification_ui_manager()->balloon_collection());
+  collection_ = static_cast<BalloonCollectionImplType*>(
+      g_browser_process->notification_ui_manager()->balloon_collection());
   std::string url = web_ui_util::GetImageDataUrlFromResource(icon_resource_id);
   DCHECK(!url.empty());
   GURL tmp_gurl(url);
@@ -55,12 +60,12 @@ SystemNotification::~SystemNotification() {
 void SystemNotification::Show(const string16& message,
                               bool urgent,
                               bool sticky) {
-  Show(message, string16(), MessageCallback(), urgent, sticky);
+  Show(message, string16(), BalloonViewHost::MessageCallback(), urgent, sticky);
 }
 
 void SystemNotification::Show(const string16& message,
                               const string16& link,
-                              const MessageCallback& callback,
+                              const BalloonViewHost::MessageCallback& callback,
                               bool urgent,
                               bool sticky) {
   Notification notify = SystemNotificationFactory::Create(icon_,
@@ -68,14 +73,14 @@ void SystemNotification::Show(const string16& message,
   if (visible_) {
     // Force showing a user hidden notification on an urgent transition.
     if (urgent && !urgent_) {
-      collection_->UpdateAndShowNotification(notify);
+      if (!collection_->UpdateAndShowNotification(notify))
+        visible_ = false;  // re-show
     } else {
       collection_->UpdateNotification(notify);
     }
-  } else {
-    collection_->AddSystemNotification(notify, profile_,
-                                       sticky,
-                                       false /* no controls */);
+  }
+  if (!visible_) {
+    collection_->AddSystemNotification(notify, profile_, sticky);
     collection_->AddWebUIMessageCallback(notify, "link", callback);
   }
   visible_ = true;
diff --git a/chrome/browser/chromeos/notifications/system_notification.h b/chrome/browser/chromeos/notifications/system_notification.h
index d7e0811..ad23750 100644
--- a/chrome/browser/chromeos/notifications/system_notification.h
+++ b/chrome/browser/chromeos/notifications/system_notification.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -19,7 +19,13 @@ class Profile;
 
 namespace chromeos {
 
+#if defined(USE_AURA)
+class BalloonCollectionImplAura;
+typedef class BalloonCollectionImplAura BalloonCollectionImplType;
+#else
 class BalloonCollectionImpl;
+typedef class BalloonCollectionImpl BalloonCollectionImplType;
+#endif
 
 // The system notification object handles the display of a system notification
 
@@ -51,7 +57,8 @@ class SystemNotification {
   // Same as Show() above with a footer link at the bottom and a callback
   // for when the link is clicked.
   void Show(const string16& message, const string16& link_text,
-            const MessageCallback& callback, bool urgent, bool sticky);
+            const BalloonViewHost::MessageCallback& callback,
+            bool urgent, bool sticky);
 
   // Hide will dismiss the notification, if the notification is already
   // hidden it does nothing
@@ -82,7 +89,7 @@ class SystemNotification {
   void Init(int icon_resource_id);
 
   Profile* profile_;
-  BalloonCollectionImpl* collection_;
+  BalloonCollectionImplType* collection_;
   scoped_refptr<NotificationDelegate> delegate_;
   GURL icon_;
   string16 title_;
diff --git a/chrome/browser/chromeos/notifications/system_notification_browsertest.cc b/chrome/browser/chromeos/notifications/system_notification_browsertest.cc
new file mode 100644
index 0000000..ab51112
--- /dev/null
+++ b/chrome/browser/chromeos/notifications/system_notification_browsertest.cc
@@ -0,0 +1,154 @@
+// 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 "base/bind.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
+#include "base/string16.h"
+#include "base/string_util.h"
+#include "base/stringprintf.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chromeos/notifications/system_notification_factory.h"
+#include "chrome/browser/notifications/notification_test_util.h"
+#include "chrome/browser/notifications/notification_ui_manager.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/notification_service.h"
+#include "ui/base/x/x11_util.h"
+
+#if defined(USE_AURA)
+#include "chrome/browser/chromeos/notifications/balloon_collection_impl_aura.h"
+#include "ui/aura/root_window.h"
+#else
+#include "chrome/browser/chromeos/notifications/balloon_collection_impl.h"
+#endif
+
+#if defined(USE_AURA)
+typedef class chromeos::BalloonCollectionImplAura BalloonCollectionImplType;
+#else
+typedef class chromeos::BalloonCollectionImpl BalloonCollectionImplType;
+#endif
+
+namespace chromeos {
+
+class SystemNotificationTest : public InProcessBrowserTest {
+ public:
+  SystemNotificationTest() {}
+
+  void HandleWebUIMessage(const ListValue* value) {
+    MessageLoop::current()->Quit();
+  }
+
+ protected:
+  virtual void SetUp() {
+    InProcessBrowserTest::SetUp();
+  }
+
+  BalloonCollectionImplType* GetBalloonCollectionImpl() {
+    return static_cast<BalloonCollectionImplType*>(
+        g_browser_process->notification_ui_manager()->balloon_collection());
+  }
+
+  Notification NewMockNotification(const std::string& id) {
+    return NewMockNotification(new MockNotificationDelegate(id));
+  }
+
+  Notification NewMockNotification(NotificationDelegate* delegate) {
+    std::string text = delegate->id();
+    return SystemNotificationFactory::Create(
+        GURL(), ASCIIToUTF16(text.c_str()), ASCIIToUTF16(text.c_str()),
+        delegate);
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SystemNotificationTest);
+};
+
+IN_PROC_BROWSER_TEST_F(SystemNotificationTest, TestSystemNotification) {
+  BalloonCollectionImplType* collection = GetBalloonCollectionImpl();
+  scoped_refptr<MockNotificationDelegate> delegate(
+      new MockNotificationDelegate("power"));
+
+  EXPECT_EQ(0, collection->count());
+
+  Notification notify = NewMockNotification(delegate.get());
+  collection->AddSystemNotification(notify, browser()->profile(), true);
+
+  EXPECT_EQ(1, collection->count());
+
+  Notification update = SystemNotificationFactory::Create(
+      GURL(), ASCIIToUTF16("Title"), ASCIIToUTF16("updated"), delegate.get());
+  collection->UpdateNotification(update);
+
+  EXPECT_EQ(1, collection->count());
+
+  Notification update_and_show = SystemNotificationFactory::Create(
+      GURL(), ASCIIToUTF16("Title"), ASCIIToUTF16("updated and shown"),
+      delegate.get());
+  collection->UpdateAndShowNotification(update_and_show);
+
+  EXPECT_EQ(1, collection->count());
+
+  // Dismiss the notification.
+  collection->RemoveById(delegate->id());
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  EXPECT_EQ(0, collection->count());
+}
+
+IN_PROC_BROWSER_TEST_F(SystemNotificationTest, TestAddWebUIMessageCallback) {
+  BalloonCollectionImplType* collection = GetBalloonCollectionImpl();
+  Profile* profile = browser()->profile();
+
+  collection->AddSystemNotification(
+      NewMockNotification("1"), profile, false);
+
+  EXPECT_TRUE(collection->AddWebUIMessageCallback(
+      NewMockNotification("1"),
+      "test",
+      base::Bind(&SystemNotificationTest::HandleWebUIMessage,
+          base::Unretained(static_cast<SystemNotificationTest*>(this)))));
+
+  // Adding callback for the same message twice should fail.
+  EXPECT_FALSE(collection->AddWebUIMessageCallback(
+      NewMockNotification("1"),
+      "test",
+      base::Bind(&SystemNotificationTest::HandleWebUIMessage,
+          base::Unretained(static_cast<SystemNotificationTest*>(this)))));
+
+  // Adding callback to nonexistent notification should fail.
+  EXPECT_FALSE(collection->AddWebUIMessageCallback(
+      NewMockNotification("2"),
+      "test1",
+      base::Bind(&SystemNotificationTest::HandleWebUIMessage,
+          base::Unretained(static_cast<SystemNotificationTest*>(this)))));
+}
+
+// Occasional crash: http://crbug.com/96461
+IN_PROC_BROWSER_TEST_F(SystemNotificationTest, TestWebUIMessageCallback) {
+  BalloonCollectionImplType* collection = GetBalloonCollectionImpl();
+  Profile* profile = browser()->profile();
+  // A notification that sends 'test' WebUI message back to chrome.
+  const GURL content_url(
+      "data:text/html;charset=utf-8,"
+      "<html><script>function send() { chrome.send('test', ['']); }</script>"
+      "<body onload='send()'></body></html>");
+  collection->AddSystemNotification(
+      Notification(GURL(), content_url, string16(), string16(),
+                   new MockNotificationDelegate("1")),
+      profile,
+      false);
+  EXPECT_TRUE(collection->AddWebUIMessageCallback(
+      NewMockNotification("1"),
+      "test",
+      base::Bind(&SystemNotificationTest::HandleWebUIMessage,
+          base::Unretained(static_cast<SystemNotificationTest*>(this)))));
+  MessageLoop::current()->Run();
+}
+
+}  // namespace chromeos
diff --git a/chrome/browser/notifications/balloon_collection_base.cc b/chrome/browser/notifications/balloon_collection_base.cc
index 4e9ab50f..278f4a9 100644
--- a/chrome/browser/notifications/balloon_collection_base.cc
+++ b/chrome/browser/notifications/balloon_collection_base.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -16,8 +16,11 @@ BalloonCollectionBase::~BalloonCollectionBase() {
   STLDeleteElements(&balloons_);
 }
 
-void BalloonCollectionBase::Add(Balloon* balloon) {
-  balloons_.push_back(balloon);
+void BalloonCollectionBase::Add(Balloon* balloon, bool add_to_front) {
+  if (add_to_front)
+    balloons_.push_front(balloon);
+  else
+    balloons_.push_back(balloon);
 }
 
 void BalloonCollectionBase::Remove(Balloon* balloon) {
diff --git a/chrome/browser/notifications/balloon_collection_base.h b/chrome/browser/notifications/balloon_collection_base.h
index c388ac9..578c76e 100644
--- a/chrome/browser/notifications/balloon_collection_base.h
+++ b/chrome/browser/notifications/balloon_collection_base.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -27,7 +27,7 @@ class BalloonCollectionBase {
   typedef std::deque<Balloon*> Balloons;
 
   // Adds a balloon to the collection. Takes ownership of pointer.
-  virtual void Add(Balloon* balloon);
+  virtual void Add(Balloon* balloon, bool add_to_front);
 
   // Removes a balloon from the collection (if present).  Frees
   // the pointer after removal.
diff --git a/chrome/browser/notifications/balloon_collection_impl.cc b/chrome/browser/notifications/balloon_collection_impl.cc
index 26e1363..b12548f 100644
--- a/chrome/browser/notifications/balloon_collection_impl.cc
+++ b/chrome/browser/notifications/balloon_collection_impl.cc
@@ -58,8 +58,9 @@ BalloonCollectionImpl::BalloonCollectionImpl()
 BalloonCollectionImpl::~BalloonCollectionImpl() {
 }
 
-void BalloonCollectionImpl::Add(const Notification& notification,
-                                Profile* profile) {
+void BalloonCollectionImpl::AddImpl(const Notification& notification,
+                                    Profile* profile,
+                                    bool add_to_front) {
   Balloon* new_balloon = MakeBalloon(notification, profile);
   // The +1 on width is necessary because width is fixed on notifications,
   // so since we always have the max size, we would always hit the scrollbar
@@ -73,7 +74,7 @@ void BalloonCollectionImpl::Add(const Notification& notification,
   if (count > 0 && layout_.RequiresOffsets())
     new_balloon->set_offset(base_.balloons()[count - 1]->offset());
 #endif
-  base_.Add(new_balloon);
+  base_.Add(new_balloon, add_to_front);
   PositionBalloons(false);
 
   // There may be no listener in a unit test.
@@ -85,6 +86,11 @@ void BalloonCollectionImpl::Add(const Notification& notification,
     on_collection_changed_callback_.Run();
 }
 
+void BalloonCollectionImpl::Add(const Notification& notification,
+                                Profile* profile) {
+  AddImpl(notification, profile, false);
+}
+
 bool BalloonCollectionImpl::RemoveById(const std::string& id) {
   return base_.CloseById(id);
 }
diff --git a/chrome/browser/notifications/balloon_collection_impl.h b/chrome/browser/notifications/balloon_collection_impl.h
index 032fabb..749c9e0 100644
--- a/chrome/browser/notifications/balloon_collection_impl.h
+++ b/chrome/browser/notifications/balloon_collection_impl.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -72,6 +72,10 @@ class BalloonCollectionImpl : public BalloonCollection,
   virtual void DidProcessEvent(GdkEvent* event) OVERRIDE;
 #endif
 
+  // base_ is embedded, so this is a simple accessor for the number of
+  // balloons in the collection.
+  int count() const { return base_.count(); }
+
  protected:
   // Calculates layout values for the balloons including
   // the scaling, the max/min sizes, and the upper left corner of each.
@@ -165,14 +169,23 @@ class BalloonCollectionImpl : public BalloonCollection,
     DISALLOW_COPY_AND_ASSIGN(Layout);
   };
 
-  // Creates a new balloon. Overridable by unit tests.  The caller is
-  // responsible for freeing the pointer returned.
+  // Creates a new balloon. Overridable by derived classes and unit tests.
+  // The caller is responsible for freeing the pointer returned.
   virtual Balloon* MakeBalloon(const Notification& notification,
                                Profile* profile);
 
+  // Protected implementation of Add with additional add_to_front parameter
+  // for use by derived classes.
+  void AddImpl(const Notification& notification,
+               Profile* profile,
+               bool add_to_front);
+
   // Gets a bounding box for all the current balloons in screen coordinates.
   gfx::Rect GetBalloonsBoundingBox() const;
 
+  BalloonCollectionBase& base() { return base_; }
+  Layout& layout() { return layout_; }
+
  private:
   // Adjusts the positions of the balloons (e.g., when one is closed).
   // Implemented by each platform for specific UI requirements.
diff --git a/chrome/browser/notifications/balloon_collection_views.cc b/chrome/browser/notifications/balloon_collection_views.cc
index f5ac0e4..763fba1 100644
--- a/chrome/browser/notifications/balloon_collection_views.cc
+++ b/chrome/browser/notifications/balloon_collection_views.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -108,7 +108,9 @@ void BalloonCollectionImpl::SetPositionPreference(
   PositionBalloons(true);
 }
 
+#if !defined(USE_AURA)
 // static
 BalloonCollection* BalloonCollection::Create() {
   return new BalloonCollectionImpl();
 }
+#endif
diff --git a/chrome/browser/notifications/notification_options_menu_model.cc b/chrome/browser/notifications/notification_options_menu_model.cc
index 2578c3f..c486742 100644
--- a/chrome/browser/notifications/notification_options_menu_model.cc
+++ b/chrome/browser/notifications/notification_options_menu_model.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -129,16 +129,18 @@ NotificationOptionsMenuModel::NotificationOptionsMenuModel(Balloon* balloon)
           IDS_EXTENSIONS_DISABLE);
       AddItem(kToggleExtensionCommand, disable_label);
     }
-  } else {
+  } else if (!notification.display_source().empty()) {
     const string16 disable_label = l10n_util::GetStringFUTF16(
         IDS_NOTIFICATION_BALLOON_REVOKE_MESSAGE,
         notification.display_source());
     AddItem(kTogglePermissionCommand, disable_label);
   }
 
-  const string16 settings_label = l10n_util::GetStringUTF16(
-      IDS_NOTIFICATIONS_SETTINGS_BUTTON);
-  AddItem(kOpenContentSettingsCommand, settings_label);
+  if (!notification.display_source().empty()) {
+    const string16 settings_label = l10n_util::GetStringUTF16(
+        IDS_NOTIFICATIONS_SETTINGS_BUTTON);
+    AddItem(kOpenContentSettingsCommand, settings_label);
+  }
 
   corner_menu_model_.reset(new CornerSelectionMenuModel(balloon));
   AddSubMenu(kCornerSelectionSubMenu,
diff --git a/chrome/browser/ui/views/notifications/balloon_view.cc b/chrome/browser/ui/views/notifications/balloon_view.cc
index 717746e..d58481d 100644
--- a/chrome/browser/ui/views/notifications/balloon_view.cc
+++ b/chrome/browser/ui/views/notifications/balloon_view.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -15,7 +15,6 @@
 #include "chrome/browser/notifications/desktop_notification_service.h"
 #include "chrome/browser/notifications/notification.h"
 #include "chrome/browser/notifications/notification_options_menu_model.h"
-#include "chrome/browser/ui/views/notifications/balloon_view_host.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/renderer_host/render_widget_host_view.h"
@@ -43,6 +42,12 @@
 #include "ui/views/painter.h"
 #include "ui/views/widget/widget.h"
 
+#if defined(OS_CHROMEOS) && defined(USE_AURA)
+#include "chrome/browser/chromeos/notifications/balloon_view_host.h"
+#else
+#include "chrome/browser/ui/views/notifications/balloon_view_host.h"
+#endif
+
 using views::Widget;
 
 namespace {
@@ -103,7 +108,8 @@ BalloonViewImpl::BalloonViewImpl(BalloonCollection* collection)
       close_button_(NULL),
       animation_(NULL),
       options_menu_model_(NULL),
-      options_menu_button_(NULL) {
+      options_menu_button_(NULL),
+      enable_web_ui_(false) {
   // This object is not to be deleted by the views hierarchy,
   // as it is owned by the balloon.
   set_parent_owned(false);
@@ -333,8 +339,15 @@ void BalloonViewImpl::Show(Balloon* balloon) {
   // We don't let the OS manage the RTL layout of these widgets, because
   // this code is already taking care of correctly reversing the layout.
   gfx::Rect contents_rect = GetContentsRectangle();
+#if defined(OS_CHROMEOS) && defined(USE_AURA)
+  html_contents_.reset(new chromeos::BalloonViewHost(balloon));
+#else
   html_contents_.reset(new BalloonViewHost(balloon));
+#endif
   html_contents_->SetPreferredSize(gfx::Size(10000, 10000));
+  if (enable_web_ui_)
+    html_contents_->EnableWebUI();
+
   html_container_ = new Widget;
   Widget::InitParams params(Widget::InitParams::TYPE_POPUP);
   params.bounds = contents_rect;
diff --git a/chrome/browser/ui/views/notifications/balloon_view.h b/chrome/browser/ui/views/notifications/balloon_view.h
index 76ef55c..8db76de 100644
--- a/chrome/browser/ui/views/notifications/balloon_view.h
+++ b/chrome/browser/ui/views/notifications/balloon_view.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -58,6 +58,8 @@ class BalloonViewImpl : public BalloonView,
   virtual gfx::Size GetSize() const OVERRIDE;
   virtual BalloonHost* GetHost() const OVERRIDE;
 
+  void set_enable_web_ui(bool enable) { enable_web_ui_ = enable; }
+
  private:
   // views::View interface.
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
@@ -157,6 +159,9 @@ class BalloonViewImpl : public BalloonView,
 
   content::NotificationRegistrar notification_registrar_;
 
+  // Set to true if this is browser generate web UI.
+  bool enable_web_ui_;
+
   DISALLOW_COPY_AND_ASSIGN(BalloonViewImpl);
 };
 
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index ec33793..5079ba6 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -445,7 +445,6 @@
         'browser/chromeos/cros_settings_names.h',
         'browser/chromeos/cros_settings_provider.cc',
         'browser/chromeos/cros_settings_provider.h',
-        'browser/chromeos/cros_stubs_aura.cc',
         'browser/chromeos/customization_document.cc',
         'browser/chromeos/customization_document.h',
         'browser/chromeos/dbus/bluetooth_adapter_client.cc',
@@ -704,6 +703,8 @@
         'browser/chromeos/network_message_observer.h',
         'browser/chromeos/notifications/balloon_collection_impl.cc',
         'browser/chromeos/notifications/balloon_collection_impl.h',
+        'browser/chromeos/notifications/balloon_collection_impl_aura.cc',
+        'browser/chromeos/notifications/balloon_collection_impl_aura.h',
         'browser/chromeos/notifications/balloon_view.cc',
         'browser/chromeos/notifications/balloon_view.h',
         'browser/chromeos/notifications/balloon_view_host.cc',
@@ -5350,6 +5351,14 @@
             ['exclude', '^browser/chromeos/login/views_login_display_host.cc'],
             ['exclude', '^browser/chromeos/login/wizard_in_process_browser_test.cc'],
             ['exclude', '^browser/chromeos/notifications/'],
+            ['include', '^browser/chromeos/notifications/balloon_collection_impl_aura.cc'],
+            ['include', '^browser/chromeos/notifications/balloon_collection_impl_aura.h'],
+            ['include', '^browser/chromeos/notifications/balloon_view_host.cc'],
+            ['include', '^browser/chromeos/notifications/balloon_view_host.h'],
+            ['include', '^browser/chromeos/notifications/system_notification.cc'],
+            ['include', '^browser/chromeos/notifications/system_notification.h'],
+            ['include', '^browser/chromeos/notifications/system_notification_factory.cc'],
+            ['include', '^browser/chromeos/notifications/system_notification_factory.h'],
           ],
         }],
         ['enable_plugin_installation==0', {
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 7e80c94..54eae34 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -2173,13 +2173,6 @@
             ['exclude', '^browser/plugin_download_helper_unittest.cc'],
             ['exclude', '^browser/safe_browsing/download_protection_service_unittest.cc' ],
           ],
-          'conditions': [
-            ['use_aura==1', {
-              'sources!': [
-                'browser/chromeos/notifications/desktop_notifications_unittest.cc',
-              ],
-            }],
-          ],
         }, { # else: chromeos == 0
           'sources/': [
             ['exclude', '^browser/chromeos/'],
@@ -2532,6 +2525,7 @@
         'browser/chromeos/login/wizard_in_process_browser_test.h',
         'browser/chromeos/media/media_player_browsertest.cc',
         'browser/chromeos/notifications/notification_browsertest.cc',
+        'browser/chromeos/notifications/system_notification_browsertest.cc',
         'browser/chromeos/panels/panel_browsertest.cc',
         'browser/chromeos/process_proxy/process_proxy_browsertest.cc',
         'browser/chromeos/status/accessibility_menu_button_browsertest.cc',
@@ -2889,7 +2883,7 @@
           'conditions': [
             ['use_aura==1', {
               'sources/': [
-                ['exclude', '^browser/chromeos/notifications/'],
+                ['exclude', '^browser/chromeos/notifications/notification_browsertest.cc'],
                 ['exclude', '^browser/chromeos/panels/panel_browsertest.cc'],
                 ['exclude', '^browser/ui/views/status_icons/status_tray_chromeos_browsertest.cc'],
               ],