Add a custom button to user pods on the login/lock screen.

This button is beside the password field and is shown through the
chrome.screenlockPrivate API.

BUG=320156
TEST=manual

Review URL: https://codereview.chromium.org/111013004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240626 0039d316-1c4b-4281-b951-d872f2087c98

24 files changed, 406 insertions, 9 deletions

diff --git a/chrome/browser/chromeos/login/login_display.h b/chrome/browser/chromeos/login/login_display.h
index dff5b4a..6958bf8 100644
--- a/chrome/browser/chromeos/login/login_display.h
+++ b/chrome/browser/chromeos/login/login_display.h
@@ -8,11 +8,13 @@
 #include <string>
 #include <vector>
 
+#include "base/callback.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/chromeos/login/help_app_launcher.h"
 #include "chrome/browser/chromeos/login/remove_user_delegate.h"
 #include "chrome/browser/chromeos/login/user.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
+#include "ui/gfx/image/image.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/rect.h"
 
@@ -146,6 +148,11 @@ class LoginDisplay : public RemoveUserDelegate {
   // Displays a banner on the login screen containing |message|.
   virtual void ShowBannerMessage(const std::string& message) = 0;
 
+  // Shows a button with an icon inside the user pod of |username|.
+  virtual void ShowUserPodButton(const std::string& username,
+                                 const std::string& iconURL,
+                                 const base::Closure& click_callback) = 0;
+
   // Displays simple error bubble with |error_msg_id| specified.
   // |login_attempts| shows number of login attempts made by current user.
   // |help_topic_id| is additional help topic that is presented as link.
diff --git a/chrome/browser/chromeos/login/mock_login_display.h b/chrome/browser/chromeos/login/mock_login_display.h
index 632d202..ee1cd966 100644
--- a/chrome/browser/chromeos/login/mock_login_display.h
+++ b/chrome/browser/chromeos/login/mock_login_display.h
@@ -25,6 +25,9 @@ class MockLoginDisplay : public LoginDisplay {
   MOCK_METHOD1(SetUIEnabled, void(bool));
   MOCK_METHOD1(SelectPod, void(int));
   MOCK_METHOD1(ShowBannerMessage, void(const std::string&));
+  MOCK_METHOD3(ShowUserPodButton, void(const std::string&,
+                                       const std::string&,
+                                       const base::Closure&));
   MOCK_METHOD3(ShowError, void(int, int, HelpAppLauncher::HelpTopic));
   MOCK_METHOD1(ShowErrorScreen, void(LoginDisplay::SigninError));
   MOCK_METHOD1(ShowGaiaPasswordChanged, void(const std::string&));
diff --git a/chrome/browser/chromeos/login/screen_locker.cc b/chrome/browser/chromeos/login/screen_locker.cc
index 7e61d01..33a0ee3 100644
--- a/chrome/browser/chromeos/login/screen_locker.cc
+++ b/chrome/browser/chromeos/login/screen_locker.cc
@@ -36,18 +36,22 @@
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
+#include "chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.h"
+#include "chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.h"
 #include "chrome/common/chrome_switches.h"
 #include "chromeos/audio/chromeos_sounds.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
+#include "content/public/browser/url_data_source.h"
 #include "content/public/browser/user_metrics.h"
 #include "grit/browser_resources.h"
 #include "grit/generated_resources.h"
 #include "media/audio/sounds/sounds_manager.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/image/image.h"
 #include "url/gurl.h"
 
 using content::BrowserThread;
@@ -181,6 +185,14 @@ void ScreenLocker::Init() {
   authenticator_ = LoginUtils::Get()->CreateAuthenticator(this);
   delegate_.reset(new WebUIScreenLocker(this));
   delegate_->LockScreen();
+
+  // Ownership of |icon_image_source| is passed.
+  screenlock_icon_provider_.reset(new ScreenlockIconProvider);
+  ScreenlockIconSource* screenlock_icon_source =
+      new ScreenlockIconSource(screenlock_icon_provider_->AsWeakPtr());
+  content::URLDataSource::Add(
+      Profile::FromWebUI(GetAssociatedWebUI()),
+      screenlock_icon_source);
 }
 
 void ScreenLocker::OnLoginFailure(const LoginFailure& error) {
@@ -302,6 +314,19 @@ void ScreenLocker::ShowBannerMessage(const std::string& message) {
   delegate_->ShowBannerMessage(message);
 }
 
+void ScreenLocker::ShowUserPodButton(const std::string& username,
+                                     const gfx::Image& icon,
+                                     const base::Closure& click_callback) {
+  if (!locked_)
+    return;
+
+  screenlock_icon_provider_->AddIcon(username, icon);
+  delegate_->ShowUserPodButton(
+      username,
+      ScreenlockIconSource::GetIconURLForUser(username),
+      click_callback);
+}
+
 void ScreenLocker::ShowErrorMessage(int error_msg_id,
                                     HelpAppLauncher::HelpTopic help_topic_id,
                                     bool sign_out_only) {
diff --git a/chrome/browser/chromeos/login/screen_locker.h b/chrome/browser/chromeos/login/screen_locker.h
index 89ddac9e..33fa3a5 100644
--- a/chrome/browser/chromeos/login/screen_locker.h
+++ b/chrome/browser/chromeos/login/screen_locker.h
@@ -7,6 +7,7 @@
 
 #include <string>
 
+#include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ -22,10 +23,15 @@ namespace content {
 class WebUI;
 }
 
+namespace gfx {
+class Image;
+}
+
 namespace chromeos {
 
 class Authenticator;
 class LoginFailure;
+class ScreenlockIconProvider;
 
 namespace test {
 class ScreenLockerTester;
@@ -78,6 +84,11 @@ class ScreenLocker : public LoginStatusConsumer {
   // Displays |message| in a banner on the lock screen.
   void ShowBannerMessage(const std::string& message);
 
+  // Shows a button inside the user pod on the lock screen with an icon.
+  void ShowUserPodButton(const std::string& username,
+                         const gfx::Image& icon,
+                         const base::Closure& click_callback);
+
   // Disables all UI needed and shows error bubble with |message|.
   // If |sign_out_only| is true then all other input except "Sign Out"
   // button is blocked.
@@ -172,6 +183,9 @@ class ScreenLocker : public LoginStatusConsumer {
   // UnlockOnLoginSuccess().
   scoped_ptr<AuthenticationParametersCapture> authentication_capture_;
 
+  // Provider for button icon set by the screenlockPrivate API.
+  scoped_ptr<ScreenlockIconProvider> screenlock_icon_provider_;
+
   base::WeakPtrFactory<ScreenLocker> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenLocker);
diff --git a/chrome/browser/chromeos/login/screen_locker_delegate.h b/chrome/browser/chromeos/login/screen_locker_delegate.h
index 4dd0046..d26928a 100644
--- a/chrome/browser/chromeos/login/screen_locker_delegate.h
+++ b/chrome/browser/chromeos/login/screen_locker_delegate.h
@@ -5,6 +5,7 @@
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_SCREEN_LOCKER_DELEGATE_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREEN_LOCKER_DELEGATE_H_
 
+#include "base/callback_forward.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/chromeos/login/help_app_launcher.h"
 #include "ui/gfx/native_widget_types.h"
@@ -15,6 +16,10 @@ namespace content {
 class WebUI;
 }
 
+namespace gfx {
+class Image;
+}
+
 namespace chromeos {
 
 class ScreenLocker;
@@ -42,6 +47,11 @@ class ScreenLockerDelegate {
   // Displays a banner containing |message| on the lock screen.
   virtual void ShowBannerMessage(const std::string& message) = 0;
 
+  // Shows a button inside the user pod on the lock screen with an icon.
+  virtual void ShowUserPodButton(const std::string& username,
+                                 const std::string& iconURL,
+                                 const base::Closure& click_callback) = 0;
+
   // Disables all UI needed and shows error bubble with |message|.
   // If |sign_out_only| is true then all other input except "Sign Out"
   // button is blocked.
diff --git a/chrome/browser/chromeos/login/webui_login_display.cc b/chrome/browser/chromeos/login/webui_login_display.cc
index e17cee1..94b7a20 100644
--- a/chrome/browser/chromeos/login/webui_login_display.cc
+++ b/chrome/browser/chromeos/login/webui_login_display.cc
@@ -132,6 +132,15 @@ void WebUILoginDisplay::ShowBannerMessage(const std::string& message) {
   webui_handler_->ShowBannerMessage(message);
 }
 
+void WebUILoginDisplay::ShowUserPodButton(
+    const std::string& username,
+    const std::string& iconURL,
+    const base::Closure& click_callback) {
+  if (!webui_handler_)
+    return;
+  webui_handler_->ShowUserPodButton(username, iconURL, click_callback);
+}
+
 void WebUILoginDisplay::ShowError(int error_msg_id,
                                   int login_attempts,
                                   HelpAppLauncher::HelpTopic help_topic_id) {
diff --git a/chrome/browser/chromeos/login/webui_login_display.h b/chrome/browser/chromeos/login/webui_login_display.h
index ad8d6a2..0fb97d0 100644
--- a/chrome/browser/chromeos/login/webui_login_display.h
+++ b/chrome/browser/chromeos/login/webui_login_display.h
@@ -42,6 +42,9 @@ class WebUILoginDisplay : public LoginDisplay,
   virtual void SetUIEnabled(bool is_enabled) OVERRIDE;
   virtual void SelectPod(int index) OVERRIDE;
   virtual void ShowBannerMessage(const std::string& message) OVERRIDE;
+  virtual void ShowUserPodButton(const std::string& username,
+                                 const std::string& iconURL,
+                                 const base::Closure& click_callback) OVERRIDE;
   virtual void ShowError(int error_msg_id,
                          int login_attempts,
                          HelpAppLauncher::HelpTopic help_topic_id) OVERRIDE;
diff --git a/chrome/browser/chromeos/login/webui_screen_locker.cc b/chrome/browser/chromeos/login/webui_screen_locker.cc
index 1cd167d..dad714e 100644
--- a/chrome/browser/chromeos/login/webui_screen_locker.cc
+++ b/chrome/browser/chromeos/login/webui_screen_locker.cc
@@ -104,6 +104,15 @@ void WebUIScreenLocker::ShowBannerMessage(const std::string& message) {
   login_display_->ShowBannerMessage(message);
 }
 
+void WebUIScreenLocker::ShowUserPodButton(
+    const std::string& username,
+    const std::string& iconURL,
+    const base::Closure& click_callback) {
+  if (!webui_ready_)
+    return;
+  login_display_->ShowUserPodButton(username, iconURL, click_callback);
+}
+
 void WebUIScreenLocker::ShowErrorMessage(
     int error_msg_id,
     HelpAppLauncher::HelpTopic help_topic_id) {
diff --git a/chrome/browser/chromeos/login/webui_screen_locker.h b/chrome/browser/chromeos/login/webui_screen_locker.h
index a6177bc..929ca1d 100644
--- a/chrome/browser/chromeos/login/webui_screen_locker.h
+++ b/chrome/browser/chromeos/login/webui_screen_locker.h
@@ -58,6 +58,9 @@ class WebUIScreenLocker : public WebUILoginView,
   virtual void OnAuthenticate() OVERRIDE;
   virtual void SetInputEnabled(bool enabled) OVERRIDE;
   virtual void ShowBannerMessage(const std::string& message) OVERRIDE;
+  virtual void ShowUserPodButton(const std::string& username,
+                                 const std::string& iconURL,
+                                 const base::Closure& click_callback) OVERRIDE;
   virtual void ShowErrorMessage(
       int error_msg_id,
       HelpAppLauncher::HelpTopic help_topic_id) OVERRIDE;
diff --git a/chrome/browser/resources/chromeos/login/screen_account_picker.js b/chrome/browser/resources/chromeos/login/screen_account_picker.js
index 72b5c6d..0064e46 100644
--- a/chrome/browser/resources/chromeos/login/screen_account_picker.js
+++ b/chrome/browser/resources/chromeos/login/screen_account_picker.js
@@ -30,6 +30,7 @@ login.createScreen('AccountPickerScreen', 'account-picker', function() {
       'onWallpaperLoaded',
       'removeUser',
       'showBannerMessage',
+      'showUserPodButton',
     ],
 
     preferredWidth_: 0,
@@ -239,6 +240,16 @@ login.createScreen('AccountPickerScreen', 'account-picker', function() {
       var banner = $('signin-banner');
       banner.textContent = message;
       banner.classList.toggle('message-set', true);
+    },
+
+    /**
+     * Shows a button with an icon on the user pod of |username|. This function
+     * is used by the chrome.screenlockPrivate API.
+     * @param {string} username Username of pod to add button
+     * @param {string} iconURL URL of the button icon
+     */
+    showUserPodButton: function(username, iconURL) {
+      $('pod-row').showUserPodButton(username, iconURL);
     }
   };
 });
diff --git a/chrome/browser/resources/chromeos/login/user_pod_row.css b/chrome/browser/resources/chromeos/login/user_pod_row.css
index f805e28..1f5fbf1 100644
--- a/chrome/browser/resources/chromeos/login/user_pod_row.css
+++ b/chrome/browser/resources/chromeos/login/user_pod_row.css
@@ -115,20 +115,54 @@ podrow[ncolumns='6'] .pod {
   display: none;
 }
 
+.password-area {
+  display: none;
+}
+
+.password-input-container {
+  -webkit-box-flex: 1;
+  /* This relative position is so the capslock hint is positioned correctly. */
+  position: relative;
+}
+
+.custom-button {
+  -webkit-box-align: center;
+  background-color: rgba(0, 0, 0, 0);
+  background-image: none;
+  cursor: pointer;
+  display: -webkit-box;
+  height: 40px;
+  margin: 0;
+  max-width: 40px;
+  min-height: 0;
+  min-width: 0;
+  padding: 0;
+}
+
+button.custom-button:focus:active,
+button.custom-button:focus:hover {
+  border: 1px solid transparent !important;
+}
+
+.custom-button img {
+  max-height: 100%;
+  max-width: 100%;
+}
+
 .pod input[type='password'] {
   -webkit-transition: opacity linear 150ms;
   background: white;
   border: none;
   box-sizing: border-box;
-  display: none;
+  display: inline-block;
   height: 40px;
   outline: none;
   padding: 4px 6px;
   width: 100%;
 }
 
-.pod.need-password.focused input[type='password'] {
-  display: inline-block;
+.pod.need-password.focused .password-area {
+  display: -webkit-box;
 }
 
 .pod .signin-button {
diff --git a/chrome/browser/resources/chromeos/login/user_pod_row.js b/chrome/browser/resources/chromeos/login/user_pod_row.js
index 787ff88..ed3d8ac 100644
--- a/chrome/browser/resources/chromeos/login/user_pod_row.js
+++ b/chrome/browser/resources/chromeos/login/user_pod_row.js
@@ -142,6 +142,7 @@ cr.define('login', function() {
     /** @override */
     decorate: function() {
       this.tabIndex = UserPodTabOrder.POD_INPUT;
+      this.customButton.tabIndex = UserPodTabOrder.POD_INPUT;
       this.actionBoxAreaElement.tabIndex = UserPodTabOrder.ACTION_BOX;
 
       // Mousedown has to be used instead of click to be able to prevent 'focus'
@@ -171,6 +172,9 @@ cr.define('login', function() {
             'click',
             this.handleRemoveUserConfirmationClick_.bind(this));
       }
+
+      this.customButton.addEventListener('click',
+          this.handleCustomButtonClick_.bind(this));
     },
 
     /**
@@ -361,6 +365,15 @@ cr.define('login', function() {
     },
 
     /**
+     * Gets the custom button. This button is normally hidden, but can be
+     * shown using the chrome.screenlockPrivate API.
+     * @type {!HTMLInputElement}
+     */
+    get customButton() {
+      return this.querySelector('.custom-button');
+    },
+
+    /**
      * Updates the user pod element.
      */
     update: function() {
@@ -692,6 +705,13 @@ cr.define('login', function() {
         // Prevent default so that we don't trigger 'focus' event.
         e.preventDefault();
       }
+    },
+
+    /**
+     * Called when the custom button is clicked.
+     */
+    handleCustomButtonClick_: function() {
+      chrome.send('customButtonClicked', [this.user.username]);
     }
   };
 
@@ -1201,6 +1221,26 @@ cr.define('login', function() {
     },
 
     /**
+     * Shows a button on a user pod with an icon. Clicking on this button
+     * triggers an event used by the chrome.screenlockPrivate API.
+     * @param {string} username Username of pod to add button
+     * @param {string} iconURL URL of the button icon
+     */
+    showUserPodButton: function(username, iconURL) {
+      var pod = this.getPodWithUsername_(username);
+      if (pod == null) {
+        console.error('Unable to show user pod button for ' + username +
+                      ': user pod not found.');
+        return;
+      }
+
+      pod.customButton.hidden = false;
+      var icon =
+          pod.customButton.querySelector('.custom-button-icon');
+      icon.src = iconURL;
+    },
+
+    /**
      * Called when window was resized.
      */
     onWindowResize: function() {
diff --git a/chrome/browser/resources/chromeos/login/user_pod_template.html b/chrome/browser/resources/chromeos/login/user_pod_template.html
index 6a05bda..d9ff755 100644
--- a/chrome/browser/resources/chromeos/login/user_pod_template.html
+++ b/chrome/browser/resources/chromeos/login/user_pod_template.html
@@ -3,10 +3,17 @@
     <div class="signed-in-indicator" i18n-content="signedIn" hidden></div>
     <img class="user-image" alt="">
     <div class="name"></div>
-    <input type="password" class="password"
-           i18n-values="placeholder:passwordHint">
-    <img class="capslock-hint"
-         src="chrome://theme/IDR_LOGIN_PASSWORD_CAPS_LOCK" alt="">
+    <div class="password-area">
+      <div class="password-input-container">
+        <input type="password" class="password"
+               i18n-values="placeholder:passwordHint">
+        <img class="capslock-hint"
+             src="chrome://theme/IDR_LOGIN_PASSWORD_CAPS_LOCK" alt="">
+      </div>
+      <button class="custom-button custom-appearance" hidden>
+        <img class="custom-button-icon"></img>
+      </button>
+    </div>
     <button class="signin-button" i18n-content="signinButton"></button>
     <div class="locked-indicator" hidden></div>
   </div>
diff --git a/chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.cc b/chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.cc
new file mode 100644
index 0000000..a5e771a
--- /dev/null
+++ b/chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.cc
@@ -0,0 +1,28 @@
+// 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 "chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.h"
+
+namespace chromeos {
+
+ScreenlockIconProvider::ScreenlockIconProvider() {}
+
+ScreenlockIconProvider::~ScreenlockIconProvider() {}
+
+void ScreenlockIconProvider::AddIcon(const std::string& username,
+                                     const gfx::Image& icon) {
+  user_icon_map_[username] = icon;
+}
+
+gfx::Image ScreenlockIconProvider::GetIcon(const std::string& username) {
+  if (user_icon_map_.find(username) == user_icon_map_.end())
+    return gfx::Image();
+  return user_icon_map_[username];
+}
+
+void ScreenlockIconProvider::Clear() {
+  user_icon_map_.clear();
+}
+
+}  // namespace chromeos
diff --git a/chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.h b/chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.h
new file mode 100644
index 0000000..c69713c
--- /dev/null
+++ b/chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.h
@@ -0,0 +1,42 @@
+// 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.
+
+#ifndef CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SCREENLOCK_ICON_PROVIDER_H_
+#define CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SCREENLOCK_ICON_PROVIDER_H_
+
+#include <map>
+
+#include "base/memory/weak_ptr.h"
+#include "ui/gfx/image/image.h"
+
+namespace chromeos {
+
+// Stores icon images used by the screenlockPrivate API. This class is
+// separate from ScreenlockIconSource for finer memory management.
+class ScreenlockIconProvider
+    : public base::SupportsWeakPtr<ScreenlockIconProvider> {
+ public:
+  ScreenlockIconProvider();
+  ~ScreenlockIconProvider();
+
+  // Adds an icon image for |username| to be stored.
+  void AddIcon(const std::string& username, const gfx::Image& icon);
+
+  // Returns the icon image set for |username|. If no icon is found, then
+  // this function returns an empty image.
+  gfx::Image GetIcon(const std::string& username);
+
+  // Removes all stored icon images.
+  void Clear();
+
+ private:
+  // Map of icons for the user pod buttons set by screenlockPrivate.showButton.
+  std::map<std::string, gfx::Image> user_icon_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScreenlockIconProvider);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SCREENLOCK_ICON_PROVIDER_H_
diff --git a/chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.cc b/chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.cc
new file mode 100644
index 0000000..d6ec467
--- /dev/null
+++ b/chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.cc
@@ -0,0 +1,70 @@
+// 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 "chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.h"
+
+#include "chrome/browser/chromeos/login/screen_locker.h"
+#include "chrome/browser/ui/webui/chromeos/login/screenlock_icon_provider.h"
+#include "chrome/common/url_constants.h"
+#include "net/base/escape.h"
+
+namespace {
+
+gfx::Image GetDefaultIcon() {
+  return gfx::Image();
+}
+
+}  // namespace
+
+namespace chromeos {
+
+////////////////////////////////////////////////////////////////////////////////
+// ScreenlockIconSource
+
+ScreenlockIconSource::ScreenlockIconSource(
+    base::WeakPtr<ScreenlockIconProvider> icon_provider)
+    : icon_provider_(icon_provider) {
+}
+
+ScreenlockIconSource::~ScreenlockIconSource() {}
+
+std::string ScreenlockIconSource::GetSource() const {
+  return std::string(chrome::kChromeUIScreenlockIconHost);
+}
+
+void ScreenlockIconSource::StartDataRequest(
+    const std::string& path,
+    int render_process_id,
+    int render_view_id,
+    const content::URLDataSource::GotDataCallback& callback) {
+  if (!icon_provider_) {
+    callback.Run(GetDefaultIcon().As1xPNGBytes());
+    return;
+  }
+
+  std::string username = net::UnescapeURLComponent(
+      path,
+      net::UnescapeRule::URL_SPECIAL_CHARS | net::UnescapeRule::SPACES);
+
+  gfx::Image image = icon_provider_->GetIcon(username);
+  if (image.IsEmpty()) {
+    callback.Run(GetDefaultIcon().As1xPNGBytes());
+    return;
+  }
+
+  callback.Run(image.As1xPNGBytes().get());
+}
+
+std::string ScreenlockIconSource::GetMimeType(const std::string&) const {
+  return "image/png";
+}
+
+// static.
+std::string ScreenlockIconSource::GetIconURLForUser(
+    const std::string& username) {
+  return std::string(chrome::kChromeUIScreenlockIconURL) +
+      net::EscapePath(username);
+}
+
+}  // namespace chromeos
diff --git a/chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.h b/chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.h
new file mode 100644
index 0000000..fcabc2d
--- /dev/null
+++ b/chrome/browser/ui/webui/chromeos/login/screenlock_icon_source.h
@@ -0,0 +1,44 @@
+// 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.
+
+#ifndef CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SCREENLOCK_ICON_SOURCE_H_
+#define CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SCREENLOCK_ICON_SOURCE_H_
+
+#include "base/memory/weak_ptr.h"
+#include "content/public/browser/url_data_source.h"
+
+namespace chromeos {
+
+class ScreenlockIconProvider;
+
+// A URL data source that serves icon images for the screenlockPrivate API.
+class ScreenlockIconSource : public content::URLDataSource {
+ public:
+  explicit ScreenlockIconSource(
+      base::WeakPtr<ScreenlockIconProvider> icon_provider);
+
+  // content::URLDataSource implementation.
+  virtual std::string GetSource() const OVERRIDE;
+  virtual void StartDataRequest(
+      const std::string& path,
+      int render_process_id,
+      int render_view_id,
+      const content::URLDataSource::GotDataCallback& callback) OVERRIDE;
+
+  virtual std::string GetMimeType(const std::string& path) const OVERRIDE;
+
+  // Constructs and returns the icon URL for a given user.
+  static std::string GetIconURLForUser(const std::string& username);
+
+ private:
+  virtual ~ScreenlockIconSource();
+
+  base::WeakPtr<ScreenlockIconProvider> icon_provider_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScreenlockIconSource);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_SCREENLOCK_ICON_SOURCE_H_
diff --git a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
index bdc49e9..abdd3de 100644
--- a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
@@ -805,6 +805,8 @@ void SigninScreenHandler::RegisterMessages() {
   AddCallback("updateOfflineLogin",
               &SigninScreenHandler::HandleUpdateOfflineLogin);
   AddCallback("focusPod", &SigninScreenHandler::HandleFocusPod);
+  AddCallback("customButtonClicked",
+              &SigninScreenHandler::HandleCustomButtonClicked);
 
   // This message is sent by the kiosk app menu, but is handled here
   // so we can tell the delegate to launch the app.
@@ -870,6 +872,14 @@ void SigninScreenHandler::ShowBannerMessage(const std::string& message) {
   CallJS("login.AccountPickerScreen.showBannerMessage", message);
 }
 
+void SigninScreenHandler::ShowUserPodButton(
+    const std::string& username,
+    const std::string& iconURL,
+    const base::Closure& click_callback) {
+  user_pod_button_callback_map_[username] = click_callback;
+  CallJS("login.AccountPickerScreen.showUserPodButton", username, iconURL);
+}
+
 void SigninScreenHandler::ShowError(int login_attempts,
                                     const std::string& error_text,
                                     const std::string& help_link_text,
@@ -1503,6 +1513,16 @@ void SigninScreenHandler::HandleFocusPod(const std::string& user_id) {
   SetUserInputMethod(user_id);
 }
 
+void SigninScreenHandler::HandleCustomButtonClicked(
+    const std::string& username) {
+  if (user_pod_button_callback_map_.find(username)
+      == user_pod_button_callback_map_.end()) {
+    LOG(WARNING) << "User pod custom button clicked but no callback found";
+    return;
+  }
+  user_pod_button_callback_map_[username].Run();
+}
+
 void SigninScreenHandler::HandleLaunchKioskApp(const std::string& app_id) {
   delegate_->LoginAsKioskApp(app_id);
 }
diff --git a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
index 27e1a14..3aa2b74 100644
--- a/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h
@@ -74,6 +74,9 @@ class LoginDisplayWebUIHandler {
   virtual void OnPreferencesChanged() = 0;
   virtual void ResetSigninScreenHandlerDelegate() = 0;
   virtual void ShowBannerMessage(const std::string& message) = 0;
+  virtual void ShowUserPodButton(const std::string& username,
+                                 const std::string& iconURL,
+                                 const base::Closure& click_callback) = 0;
   virtual void ShowError(int login_attempts,
                          const std::string& error_text,
                          const std::string& help_link_text,
@@ -276,6 +279,9 @@ class SigninScreenHandler
   virtual void OnPreferencesChanged() OVERRIDE;
   virtual void ResetSigninScreenHandlerDelegate() OVERRIDE;
   virtual void ShowBannerMessage(const std::string& message) OVERRIDE;
+  virtual void ShowUserPodButton(const std::string& username,
+                                 const std::string& iconURL,
+                                 const base::Closure& click_callback) OVERRIDE;
   virtual void ShowError(int login_attempts,
                          const std::string& error_text,
                          const std::string& help_link_text,
@@ -356,6 +362,7 @@ class SigninScreenHandler
   void HandleShowLocallyManagedUserCreationScreen();
   void HandleFocusPod(const std::string& user_id);
   void HandleLaunchKioskApp(const std::string& app_id);
+  void HandleCustomButtonClicked(const std::string& username);
 
   // Fills |user_dict| with information about |user|.
   static void FillUserDictionary(User* user,
@@ -505,6 +512,9 @@ class SigninScreenHandler
 
   base::Closure kiosk_enable_flow_aborted_callback_for_test_;
 
+  // Map of callbacks run when the custom button on a user pod is clicked.
+  std::map<std::string, base::Closure> user_pod_button_callback_map_;
+
   // Non-owning ptr.
   // TODO (ygorshenin@): remove this dependency.
   GaiaScreenHandler* gaia_screen_handler_;
diff --git a/chrome/chrome_browser_chromeos.gypi b/chrome/chrome_browser_chromeos.gypi
index b0250df..345f0f6 100644
--- a/chrome/chrome_browser_chromeos.gypi
+++ b/chrome/chrome_browser_chromeos.gypi
@@ -921,6 +921,8 @@
             'browser/chromeos/extensions/first_run_private_api.h',
             'browser/chromeos/extensions/input_method_api.cc',
             'browser/chromeos/extensions/input_method_api.h',
+            'browser/chromeos/extensions/screenlock_private_api.cc',
+            'browser/chromeos/extensions/screenlock_private_api.h',
             'browser/chromeos/extensions/media_player_api.cc',
             'browser/chromeos/extensions/media_player_api.h',
             'browser/chromeos/extensions/wallpaper_manager_util.cc',
diff --git a/chrome/chrome_browser_extensions.gypi b/chrome/chrome_browser_extensions.gypi
index 950f99e..0a28b36 100644
--- a/chrome/chrome_browser_extensions.gypi
+++ b/chrome/chrome_browser_extensions.gypi
@@ -934,8 +934,6 @@
             'browser/extensions/api/log_private/log_private_api_chromeos.cc',
             'browser/extensions/api/log_private/syslog_parser.cc',
             'browser/extensions/api/log_private/syslog_parser.h',
-            'browser/chromeos/extensions/screenlock_private_api.cc',
-            'browser/chromeos/extensions/screenlock_private_api.h',
             'browser/extensions/api/networking_private/networking_private_api_chromeos.cc',
             'browser/extensions/api/networking_private/networking_private_api.h',
             'browser/extensions/api/networking_private/networking_private_event_router_chromeos.cc',
diff --git a/chrome/chrome_browser_ui.gypi b/chrome/chrome_browser_ui.gypi
index d2ea87c..47054c7 100644
--- a/chrome/chrome_browser_ui.gypi
+++ b/chrome/chrome_browser_ui.gypi
@@ -2245,6 +2245,10 @@
         'browser/ui/webui/chromeos/login/oobe_ui.h',
         'browser/ui/webui/chromeos/login/reset_screen_handler.cc',
         'browser/ui/webui/chromeos/login/reset_screen_handler.h',
+        'browser/ui/webui/chromeos/login/screenlock_icon_provider.cc',
+        'browser/ui/webui/chromeos/login/screenlock_icon_provider.h',
+        'browser/ui/webui/chromeos/login/screenlock_icon_source.cc',
+        'browser/ui/webui/chromeos/login/screenlock_icon_source.h',
         'browser/ui/webui/chromeos/login/screen_manager_handler.cc',
         'browser/ui/webui/chromeos/login/screen_manager_handler.h',
         'browser/ui/webui/chromeos/login/signin_screen_handler.cc',
diff --git a/chrome/common/url_constants.cc b/chrome/common/url_constants.cc
index c799c40..1e2650c 100644
--- a/chrome/common/url_constants.cc
+++ b/chrome/common/url_constants.cc
@@ -113,6 +113,7 @@ const char kChromeUIMobileSetupURL[] = "chrome://mobilesetup/";
 const char kChromeUIOobeURL[] = "chrome://oobe/";
 const char kChromeUIOSCreditsURL[] = "chrome://os-credits/";
 const char kChromeUIProxySettingsURL[] = "chrome://proxy-settings/";
+const char kChromeUIScreenlockIconURL[] = "chrome://screenlock-icon/";
 const char kChromeUISimUnlockURL[] = "chrome://sim-unlock/";
 const char kChromeUISlideshowURL[] = "chrome://slideshow/";
 const char kChromeUISlowURL[] = "chrome://slow/";
@@ -266,6 +267,7 @@ const char kChromeUIOobeHost[] = "oobe";
 const char kChromeUIOSCreditsHost[] = "os-credits";
 const char kChromeUIProxySettingsHost[] = "proxy-settings";
 const char kChromeUIRotateHost[] = "rotate";
+const char kChromeUIScreenlockIconHost[] = "screenlock-icon";
 const char kChromeUISimUnlockHost[] = "sim-unlock";
 const char kChromeUISlideshowHost[] = "slideshow";
 const char kChromeUISlowHost[] = "slow";
diff --git a/chrome/common/url_constants.h b/chrome/common/url_constants.h
index 573f947..e50f802 100644
--- a/chrome/common/url_constants.h
+++ b/chrome/common/url_constants.h
@@ -108,6 +108,7 @@ extern const char kChromeUIMobileSetupURL[];
 extern const char kChromeUIOobeURL[];
 extern const char kChromeUIOSCreditsURL[];
 extern const char kChromeUIProxySettingsURL[];
+extern const char kChromeUIScreenlockIconURL[];
 extern const char kChromeUISimUnlockURL[];
 extern const char kChromeUISlideshowURL[];
 extern const char kChromeUISlowURL[];
@@ -260,6 +261,7 @@ extern const char kChromeUIOobeHost[];
 extern const char kChromeUIOSCreditsHost[];
 extern const char kChromeUIProxySettingsHost[];
 extern const char kChromeUIRotateHost[];
+extern const char kChromeUIScreenlockIconHost[];
 extern const char kChromeUISimUnlockHost[];
 extern const char kChromeUISlideshowHost[];
 extern const char kChromeUISlowHost[];