wstring: remove wstrings from all tooltip-related code

This is a nearly-mechanical translation of wstring to string16.
Removes a *ton* of string conversions.

Review URL: http://codereview.chromium.org/7886023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@101329 0039d316-1c4b-4281-b951-d872f2087c98

93 files changed, 226 insertions, 250 deletions

diff --git a/chrome/browser/chromeos/frame/layout_mode_button.cc b/chrome/browser/chromeos/frame/layout_mode_button.cc
index 734eda2..c4381dc 100644
--- a/chrome/browser/chromeos/frame/layout_mode_button.cc
+++ b/chrome/browser/chromeos/frame/layout_mode_button.cc
@@ -85,13 +85,13 @@ void LayoutModeButton::UpdateForCurrentLayoutMode() {
   switch (mode) {
     case WM_IPC_LAYOUT_MAXIMIZED:
       SetImage(BS_NORMAL, rb.GetBitmapNamed(IDR_STATUSBAR_WINDOW_RESTORE));
-      SetTooltipText(UTF16ToWide(
-          l10n_util::GetStringUTF16(IDS_STATUSBAR_WINDOW_RESTORE_TOOLTIP)));
+      SetTooltipText(
+          l10n_util::GetStringUTF16(IDS_STATUSBAR_WINDOW_RESTORE_TOOLTIP));
       break;
     case WM_IPC_LAYOUT_OVERLAPPING:
       SetImage(BS_NORMAL, rb.GetBitmapNamed(IDR_STATUSBAR_WINDOW_MAXIMIZE));
-      SetTooltipText(UTF16ToWide(
-          l10n_util::GetStringUTF16(IDS_STATUSBAR_WINDOW_MAXIMIZE_TOOLTIP)));
+      SetTooltipText(
+          l10n_util::GetStringUTF16(IDS_STATUSBAR_WINDOW_MAXIMIZE_TOOLTIP));
       break;
     default:
       DLOG(WARNING) << "Unknown layout mode " << mode;
diff --git a/chrome/browser/chromeos/login/default_images_view.cc b/chrome/browser/chromeos/login/default_images_view.cc
index c050b17..a4d49da 100644
--- a/chrome/browser/chromeos/login/default_images_view.cc
+++ b/chrome/browser/chromeos/login/default_images_view.cc
@@ -93,8 +93,8 @@ DefaultImagesView::~DefaultImagesView() {}
 void DefaultImagesView::Init() {
   UserImageButton* capture_button = new UserImageButton(this);
   capture_button->set_id(kCaptureButtonId);
-  capture_button->SetTooltipText(UTF16ToWide(
-      l10n_util::GetStringUTF16(IDS_OPTIONS_CHANGE_PICTURE_TAKE_PHOTO)));
+  capture_button->SetTooltipText(
+      l10n_util::GetStringUTF16(IDS_OPTIONS_CHANGE_PICTURE_TAKE_PHOTO));
   InitButton(IDR_BUTTON_USER_IMAGE_TAKE_PHOTO, capture_button);
   default_images_.push_back(capture_button);
   for (int i = 0; i < kDefaultImagesCount; ++i) {
diff --git a/chrome/browser/chromeos/login/eula_view.cc b/chrome/browser/chromeos/login/eula_view.cc
index dbf6522..b28640e 100644
--- a/chrome/browser/chromeos/login/eula_view.cc
+++ b/chrome/browser/chromeos/login/eula_view.cc
@@ -372,13 +372,13 @@ void EulaView::UpdateLocalizedStrings() {
   // Set tooltip for usage statistics checkbox if the metric is unmanaged.
   if (!usage_statistics_checkbox_->IsEnabled()) {
     usage_statistics_checkbox_->SetTooltipText(
-        UTF16ToWide(l10n_util::GetStringUTF16(IDS_OPTION_DISABLED_BY_POLICY)));
+        l10n_util::GetStringUTF16(IDS_OPTION_DISABLED_BY_POLICY));
   }
 
   // Set tooltip for system security settings link if TPM is disabled.
   if (!system_security_settings_link_->IsEnabled()) {
     system_security_settings_link_->SetTooltipText(
-        UTF16ToWide(l10n_util::GetStringUTF16(IDS_EULA_TPM_DISABLED)));
+        l10n_util::GetStringUTF16(IDS_EULA_TPM_DISABLED));
   }
 
   // Load other labels from resources.
diff --git a/chrome/browser/chromeos/login/keyboard_switch_menu.cc b/chrome/browser/chromeos/login/keyboard_switch_menu.cc
index 47ac9fe..ef9be17 100644
--- a/chrome/browser/chromeos/login/keyboard_switch_menu.cc
+++ b/chrome/browser/chromeos/login/keyboard_switch_menu.cc
@@ -26,7 +26,7 @@ KeyboardSwitchMenu::KeyboardSwitchMenu()
 // InputMethodMenu::InputMethodMenuHost implementation.
 void KeyboardSwitchMenu::UpdateUI(const std::string& input_method_id,
                                   const std::wstring& name,
-                                  const std::wstring& tooltip,
+                                  const string16& tooltip,
                                   size_t num_active_input_methods) {
   // Update all view hierarchies so that the new input method name is shown in
   // the menu button.
diff --git a/chrome/browser/chromeos/login/keyboard_switch_menu.h b/chrome/browser/chromeos/login/keyboard_switch_menu.h
index c103198..0f4ffc2 100644
--- a/chrome/browser/chromeos/login/keyboard_switch_menu.h
+++ b/chrome/browser/chromeos/login/keyboard_switch_menu.h
@@ -25,10 +25,10 @@ class KeyboardSwitchMenu : public InputMethodMenu {
   // InputMethodMenu::InputMethodMenuHost implementation.
   virtual void UpdateUI(const std::string& input_method_id,
                         const std::wstring& name,
-                        const std::wstring& tooltip,
-                        size_t num_active_input_methods);
-  virtual bool ShouldSupportConfigUI();
-  virtual void OpenConfigUI() {}
+                        const string16& tooltip,
+                        size_t num_active_input_methods) OVERRIDE;
+  virtual bool ShouldSupportConfigUI() OVERRIDE;
+  virtual void OpenConfigUI() OVERRIDE {}
 
   // views::ViewMenuDelegate implementation which overrides the implementation
   // in InputMethodMenu.
diff --git a/chrome/browser/chromeos/login/screen_lock_view.cc b/chrome/browser/chromeos/login/screen_lock_view.cc
index 57f0f89..00f88e8 100644
--- a/chrome/browser/chromeos/login/screen_lock_view.cc
+++ b/chrome/browser/chromeos/login/screen_lock_view.cc
@@ -160,8 +160,7 @@ void ScreenLockView::Init() {
 
   // Add tooltip if screen name is not unique.
   if (user.NeedsNameTooltip()) {
-    const std::wstring tooltip_text = UTF8ToWide(user.GetNameTooltip());
-
+    string16 tooltip_text = UTF8ToUTF16(user.GetNameTooltip());
     user_view_->SetTooltipText(tooltip_text);
     username->SetTooltipText(tooltip_text);
   }
diff --git a/chrome/browser/chromeos/login/user_controller.cc b/chrome/browser/chromeos/login/user_controller.cc
index 4e6645a..069cdc9 100644
--- a/chrome/browser/chromeos/login/user_controller.cc
+++ b/chrome/browser/chromeos/login/user_controller.cc
@@ -190,7 +190,7 @@ void UserController::ClearAndEnablePassword() {
 
 void UserController::EnableNameTooltip(bool enable) {
   name_tooltip_enabled_ = enable;
-  std::wstring tooltip_text;
+  string16 tooltip_text;
   if (enable)
     tooltip_text = GetNameTooltip();
 
@@ -519,14 +519,13 @@ gfx::Font UserController::GetUnselectedLabelFont() {
       kUnselectedUsernameFontDelta, gfx::Font::BOLD);
 }
 
-
-std::wstring UserController::GetNameTooltip() const {
+string16 UserController::GetNameTooltip() const {
   if (is_new_user_)
-    return UTF16ToWide(l10n_util::GetStringUTF16(IDS_ADD_USER));
+    return l10n_util::GetStringUTF16(IDS_ADD_USER);
   else if (is_guest_)
-    return UTF16ToWide(l10n_util::GetStringUTF16(IDS_GO_INCOGNITO_BUTTON));
+    return l10n_util::GetStringUTF16(IDS_GO_INCOGNITO_BUTTON);
   else
-    return UTF8ToWide(user_.GetNameTooltip());
+    return UTF8ToUTF16(user_.GetNameTooltip());
 }
 
 }  // namespace chromeos
diff --git a/chrome/browser/chromeos/login/user_controller.h b/chrome/browser/chromeos/login/user_controller.h
index 0278d78..9bfe948 100644
--- a/chrome/browser/chromeos/login/user_controller.h
+++ b/chrome/browser/chromeos/login/user_controller.h
@@ -167,7 +167,7 @@ class UserController : public views::WidgetDelegate,
                           int controls_width, int controls_height);
 
   // Returns tooltip text for user name.
-  std::wstring GetNameTooltip() const;
+  string16 GetNameTooltip() const;
 
   // Creates the widget that holds the controls. Caller owns the returned
   // widget.
diff --git a/chrome/browser/chromeos/login/user_controller_unittest.cc b/chrome/browser/chromeos/login/user_controller_unittest.cc
index 74642fc2..6b8ce18 100644
--- a/chrome/browser/chromeos/login/user_controller_unittest.cc
+++ b/chrome/browser/chromeos/login/user_controller_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -15,13 +15,13 @@ namespace chromeos {
 
 TEST(UserControllerTest, GetNameTooltipAddUser) {
   UserController guest_user_controller(NULL, false);
-  EXPECT_EQ(UTF16ToWide(l10n_util::GetStringUTF16(IDS_ADD_USER)),
+  EXPECT_EQ(l10n_util::GetStringUTF16(IDS_ADD_USER),
             guest_user_controller.GetNameTooltip());
 }
 
 TEST(UserControllerTest, GetNameTooltipIncognitoUser) {
   UserController new_user_controller(NULL, true);
-  EXPECT_EQ(UTF16ToWide(l10n_util::GetStringUTF16(IDS_GO_INCOGNITO_BUTTON)),
+  EXPECT_EQ(l10n_util::GetStringUTF16(IDS_GO_INCOGNITO_BUTTON),
             new_user_controller.GetNameTooltip());
 }
 
@@ -32,7 +32,7 @@ TEST(UserControllerTest, GetNameTooltipExistingUser) {
   UserManager::User existing_user;
   existing_user.set_email("someordinaryuser@domain.com");
   UserController existing_user_controller(NULL, existing_user);
-  EXPECT_EQ(L"someordinaryuser (domain.com)",
+  EXPECT_EQ(ASCIIToUTF16("someordinaryuser (domain.com)"),
             existing_user_controller.GetNameTooltip());
 }
 
diff --git a/chrome/browser/chromeos/login/user_view.cc b/chrome/browser/chromeos/login/user_view.cc
index 352a42a..c2d72f7 100644
--- a/chrome/browser/chromeos/login/user_view.cc
+++ b/chrome/browser/chromeos/login/user_view.cc
@@ -301,7 +301,7 @@ void UserView::SetImage(const SkBitmap& image, const SkBitmap& image_hot) {
   image_view_->SetImage(image, image_hot);
 }
 
-void UserView::SetTooltipText(const std::wstring& text) {
+void UserView::SetTooltipText(const string16& text) {
   DCHECK(image_view_);
   image_view_->SetTooltipText(text);
 }
diff --git a/chrome/browser/chromeos/login/user_view.h b/chrome/browser/chromeos/login/user_view.h
index b33e359..8b67a90 100644
--- a/chrome/browser/chromeos/login/user_view.h
+++ b/chrome/browser/chromeos/login/user_view.h
@@ -63,7 +63,7 @@ class UserView : public views::View,
   void SetImage(const SkBitmap& image, const SkBitmap& image_hot);
 
   // Sets tooltip over the image.
-  void SetTooltipText(const std::wstring& text);
+  void SetTooltipText(const string16& text);
 
   // Show/Hide remove button.
   void SetRemoveButtonVisible(bool flag);
diff --git a/chrome/browser/chromeos/options/wifi_config_view.cc b/chrome/browser/chromeos/options/wifi_config_view.cc
index d1c8e99..fa1199e 100644
--- a/chrome/browser/chromeos/options/wifi_config_view.cc
+++ b/chrome/browser/chromeos/options/wifi_config_view.cc
@@ -877,11 +877,11 @@ void WifiConfigView::Init(WifiNetwork* wifi, bool show_8021x) {
   // Password visible button.
   passphrase_visible_button_ = new views::ToggleImageButton(this);
   passphrase_visible_button_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(
-          IDS_OPTIONS_SETTINGS_INTERNET_OPTIONS_PASSPHRASE_SHOW)));
+      l10n_util::GetStringUTF16(
+          IDS_OPTIONS_SETTINGS_INTERNET_OPTIONS_PASSPHRASE_SHOW));
   passphrase_visible_button_->SetToggledTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(
-          IDS_OPTIONS_SETTINGS_INTERNET_OPTIONS_PASSPHRASE_HIDE)));
+      l10n_util::GetStringUTF16(
+          IDS_OPTIONS_SETTINGS_INTERNET_OPTIONS_PASSPHRASE_HIDE));
   passphrase_visible_button_->SetImage(
       views::ImageButton::BS_NORMAL,
       ResourceBundle::GetSharedInstance().
diff --git a/chrome/browser/chromeos/status/accessibility_menu_button.cc b/chrome/browser/chromeos/status/accessibility_menu_button.cc
index 867f758..4ffbb5e 100644
--- a/chrome/browser/chromeos/status/accessibility_menu_button.cc
+++ b/chrome/browser/chromeos/status/accessibility_menu_button.cc
@@ -86,7 +86,7 @@ void AccessibilityMenuButton::Update() {
   // Update tooltip and accessibile name.
   string16 message =
       l10n_util::GetStringUTF16(IDS_STATUSBAR_ACCESSIBILITY_ENABLED);
-  SetTooltipText(UTF16ToWide(message));
+  SetTooltipText(message);
   SetAccessibleName(message);
   // Update visibility.
   SetVisible(accessibility_enabled_.GetValue());
diff --git a/chrome/browser/chromeos/status/caps_lock_menu_button.cc b/chrome/browser/chromeos/status/caps_lock_menu_button.cc
index 50db80c..7509d8a 100644
--- a/chrome/browser/chromeos/status/caps_lock_menu_button.cc
+++ b/chrome/browser/chromeos/status/caps_lock_menu_button.cc
@@ -86,7 +86,7 @@ void CapsLockMenuButton::UpdateTooltip() {
   int id = IDS_STATUSBAR_CAPS_LOCK_ENABLED;
   if (prefs_ && (remap_search_key_to_.GetValue() == input_method::kCapsLockKey))
     id = IDS_STATUSBAR_CAPS_LOCK_ENABLED_PRESS_SEARCH;
-  SetTooltipText(UTF16ToWide(l10n_util::GetStringUTF16(id)));
+  SetTooltipText(l10n_util::GetStringUTF16(id));
   SetAccessibleName(l10n_util::GetStringUTF16(id));
 }
 
diff --git a/chrome/browser/chromeos/status/clock_menu_button.cc b/chrome/browser/chromeos/status/clock_menu_button.cc
index 94f309c..dd3f3cf 100644
--- a/chrome/browser/chromeos/status/clock_menu_button.cc
+++ b/chrome/browser/chromeos/status/clock_menu_button.cc
@@ -95,7 +95,7 @@ void ClockMenuButton::UpdateText() {
       time,
       use_24hour_clock ? base::k24HourClock : base::k12HourClock,
       base::kDropAmPm)));
-  SetTooltipText(UTF16ToWide(base::TimeFormatFriendlyDateAndTime(time)));
+  SetTooltipText(base::TimeFormatFriendlyDateAndTime(time));
   SetAccessibleName(base::TimeFormatFriendlyDateAndTime(time));
   SchedulePaint();
 }
diff --git a/chrome/browser/chromeos/status/input_method_menu.cc b/chrome/browser/chromeos/status/input_method_menu.cc
index ff42f3e..da7c7f6 100644
--- a/chrome/browser/chromeos/status/input_method_menu.cc
+++ b/chrome/browser/chromeos/status/input_method_menu.cc
@@ -498,7 +498,7 @@ void InputMethodMenu::UpdateUIFromInputMethod(
     const input_method::InputMethodDescriptor& input_method,
     size_t num_active_input_methods) {
   const std::wstring name = GetTextForIndicator(input_method);
-  const std::wstring tooltip = GetTextForMenu(input_method);
+  const string16 tooltip = WideToUTF16Hack(GetTextForMenu(input_method));
   UpdateUI(input_method.id(), name, tooltip, num_active_input_methods);
 }
 
diff --git a/chrome/browser/chromeos/status/input_method_menu.h b/chrome/browser/chromeos/status/input_method_menu.h
index 0382380..c2ae9ac 100644
--- a/chrome/browser/chromeos/status/input_method_menu.h
+++ b/chrome/browser/chromeos/status/input_method_menu.h
@@ -127,7 +127,7 @@ class InputMethodMenu : public views::ViewMenuDelegate,
   // status area). Sub classes have to implement the interface for their own UI.
   virtual void UpdateUI(const std::string& input_method_id,  // e.g. "mozc"
                         const std::wstring& name,  // e.g. "US", "INTL"
-                        const std::wstring& tooltip,
+                        const string16& tooltip,
                         size_t num_active_input_methods) = 0;
 
   // Sub classes have to implement the interface. This interface should return
diff --git a/chrome/browser/chromeos/status/input_method_menu_button.cc b/chrome/browser/chromeos/status/input_method_menu_button.cc
index 1a45e4a..f4c124e 100644
--- a/chrome/browser/chromeos/status/input_method_menu_button.cc
+++ b/chrome/browser/chromeos/status/input_method_menu_button.cc
@@ -41,7 +41,7 @@ class MenuImpl : public chromeos::InputMethodMenu {
   // InputMethodMenu implementation.
   virtual void UpdateUI(const std::string& input_method_id,
                         const std::wstring& name,
-                        const std::wstring& tooltip,
+                        const string16& tooltip,
                         size_t num_active_input_methods) {
     button_->UpdateUI(input_method_id, name, tooltip, num_active_input_methods);
   }
@@ -107,7 +107,7 @@ bool InputMethodMenuButton::WindowIsActive() {
 
 void InputMethodMenuButton::UpdateUI(const std::string& input_method_id,
                                      const std::wstring& name,
-                                     const std::wstring& tooltip,
+                                     const string16& tooltip,
                                      size_t num_active_input_methods) {
   // Hide the button only if there is only one input method, and the input
   // method is a XKB keyboard layout. We don't hide the button for other
@@ -120,7 +120,7 @@ void InputMethodMenuButton::UpdateUI(const std::string& input_method_id,
   SetVisible(!hide_button);
   SetText(name);
   SetTooltipText(tooltip);
-  SetAccessibleName(WideToUTF16(tooltip));
+  SetAccessibleName(tooltip);
 
   if (WindowIsActive()) {
     // We don't call these functions if the |current_window| is not active since
@@ -150,7 +150,8 @@ void InputMethodMenuButton::UpdateUIFromCurrentInputMethod() {
   const input_method::InputMethodDescriptor& input_method =
       input_method_manager->current_input_method();
   const std::wstring name = InputMethodMenu::GetTextForIndicator(input_method);
-  const std::wstring tooltip = InputMethodMenu::GetTextForMenu(input_method);
+  const string16 tooltip = WideToUTF16Hack(
+      InputMethodMenu::GetTextForMenu(input_method));
   const size_t num_active_input_methods =
       input_method_manager->GetNumActiveInputMethods();
   UpdateUI(input_method.id(), name, tooltip, num_active_input_methods);
diff --git a/chrome/browser/chromeos/status/input_method_menu_button.h b/chrome/browser/chromeos/status/input_method_menu_button.h
index eff624d3..3c14f7b 100644
--- a/chrome/browser/chromeos/status/input_method_menu_button.h
+++ b/chrome/browser/chromeos/status/input_method_menu_button.h
@@ -8,6 +8,7 @@
 
 #include <string>
 
+#include "base/compiler_specific.h"
 #include "chrome/browser/chromeos/status/input_method_menu.h"
 #include "chrome/browser/chromeos/status/status_area_button.h"
 #include "views/controls/menu/view_menu_delegate.h"
@@ -33,10 +34,10 @@ class InputMethodMenuButton : public StatusAreaButton,
   // InputMethodMenu implementation.
   virtual void UpdateUI(const std::string& input_method_id,
                         const std::wstring& name,
-                        const std::wstring& tooltip,
-                        size_t num_active_input_methods);
-  virtual bool ShouldSupportConfigUI();
-  virtual void OpenConfigUI();
+                        const string16& tooltip,
+                        size_t num_active_input_methods) OVERRIDE;
+  virtual bool ShouldSupportConfigUI() OVERRIDE;
+  virtual void OpenConfigUI() OVERRIDE;
 
   // Updates the UI from the current input method.
   void UpdateUIFromCurrentInputMethod();
diff --git a/chrome/browser/chromeos/status/memory_menu_button.cc b/chrome/browser/chromeos/status/memory_menu_button.cc
index cda69ff..6720965 100644
--- a/chrome/browser/chromeos/status/memory_menu_button.cc
+++ b/chrome/browser/chromeos/status/memory_menu_button.cc
@@ -81,12 +81,12 @@ void MemoryMenuButton::UpdateText() {
                                           anon_kb / 1024,
                                           renderer_kills_);
   SetText(label);
-  std::wstring tooltip = base::StringPrintf(
-      L"%d MB allocated (anonymous)\n"
-      L"%d renderer kill(s)",
+  std::string tooltip = base::StringPrintf(
+      "%d MB allocated (anonymous)\n"
+      "%d renderer kill(s)",
       anon_kb / 1024,
       renderer_kills_);
-  SetTooltipText(tooltip);
+  SetTooltipText(ASCIIToUTF16(tooltip));
   SchedulePaint();
 }
 
diff --git a/chrome/browser/chromeos/status/network_menu_button.cc b/chrome/browser/chromeos/status/network_menu_button.cc
index 5bac069..adc891f 100644
--- a/chrome/browser/chromeos/status/network_menu_button.cc
+++ b/chrome/browser/chromeos/status/network_menu_button.cc
@@ -435,7 +435,7 @@ void NetworkMenuButton::ShowOptionalMobileDataPromoNotification(
 }
 
 void NetworkMenuButton::SetTooltipAndAccessibleName(const string16& label) {
-  SetTooltipText(UTF16ToWide(label));
+  SetTooltipText(label);
   SetAccessibleName(label);
 }
 
diff --git a/chrome/browser/chromeos/status/power_menu_button.cc b/chrome/browser/chromeos/status/power_menu_button.cc
index 555f67d..88ca658 100644
--- a/chrome/browser/chromeos/status/power_menu_button.cc
+++ b/chrome/browser/chromeos/status/power_menu_button.cc
@@ -397,7 +397,7 @@ void PowerMenuButton::UpdateIconAndLabelInfo() {
   }
 
   percentage_text_ = GetBatteryPercentageText();
-  SetTooltipText(UTF16ToWide(percentage_text_));
+  SetTooltipText(percentage_text_);
   SetAccessibleName(percentage_text_);
   SchedulePaint();
   if (status_)
diff --git a/chrome/browser/extensions/browser_action_test_util_views.cc b/chrome/browser/extensions/browser_action_test_util_views.cc
index 1924c37..6e1aa74 100644
--- a/chrome/browser/extensions/browser_action_test_util_views.cc
+++ b/chrome/browser/extensions/browser_action_test_util_views.cc
@@ -56,10 +56,10 @@ std::string BrowserActionTestUtil::GetExtensionId(int index) {
 }
 
 std::string BrowserActionTestUtil::GetTooltip(int index) {
-  std::wstring text;
+  string16 text;
   GetContainer(browser_)->GetBrowserActionViewAt(index)->button()->
     GetTooltipText(gfx::Point(), &text);
-  return WideToUTF8(text);
+  return UTF16ToUTF8(text);
 }
 
 bool BrowserActionTestUtil::HasPopup() {
diff --git a/chrome/browser/renderer_host/render_widget_host_view_mac.h b/chrome/browser/renderer_host/render_widget_host_view_mac.h
index 71e1c53..4dcd88b 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_mac.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_mac.h
@@ -230,7 +230,7 @@ class RenderWidgetHostViewMac : public RenderWidgetHostView {
   virtual void RenderViewGone(base::TerminationStatus status,
                               int error_code) OVERRIDE;
   virtual void Destroy() OVERRIDE;
-  virtual void SetTooltipText(const std::wstring& tooltip_text) OVERRIDE;
+  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
   virtual void SelectionChanged(const std::string& text,
                                 const ui::Range& range,
                                 const gfx::Point& start,
@@ -412,7 +412,7 @@ class RenderWidgetHostViewMac : public RenderWidgetHostView {
   bool is_showing_context_menu_;
 
   // The text to be shown in the tooltip, supplied by the renderer.
-  std::wstring tooltip_text_;
+  string16 tooltip_text_;
 
   // Factory used to safely scope delayed calls to ShutdownHost().
   ScopedRunnableMethodFactory<RenderWidgetHostViewMac> shutdown_factory_;
diff --git a/chrome/browser/renderer_host/render_widget_host_view_mac.mm b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
index dcc3988..46fad6e 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
@@ -681,7 +681,7 @@ void RenderWidgetHostViewMac::Destroy() {
 // Called from the renderer to tell us what the tooltip text should be. It
 // calls us frequently so we need to cache the value to prevent doing a lot
 // of repeat work.
-void RenderWidgetHostViewMac::SetTooltipText(const std::wstring& tooltip_text) {
+void RenderWidgetHostViewMac::SetTooltipText(const string16& tooltip_text) {
   if (tooltip_text != tooltip_text_ && [[cocoa_view_ window] isKeyWindow]) {
     tooltip_text_ = tooltip_text;
 
@@ -689,11 +689,11 @@ void RenderWidgetHostViewMac::SetTooltipText(const std::wstring& tooltip_text) {
     // Windows; we're just trying to be polite. Don't persist the trimmed
     // string, as then the comparison above will always fail and we'll try to
     // set it again every single time the mouse moves.
-    std::wstring display_text = tooltip_text_;
+    string16 display_text = tooltip_text_;
     if (tooltip_text_.length() > kMaxTooltipLength)
       display_text = tooltip_text_.substr(0, kMaxTooltipLength);
 
-    NSString* tooltip_nsstring = base::SysWideToNSString(display_text);
+    NSString* tooltip_nsstring = base::SysUTF16ToNSString(display_text);
     [cocoa_view_ setToolTipAtMousePoint:tooltip_nsstring];
   }
 }
diff --git a/chrome/browser/renderer_host/render_widget_host_view_views.cc b/chrome/browser/renderer_host/render_widget_host_view_views.cc
index 6396c4b..6608f22 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_views.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_views.cc
@@ -328,12 +328,11 @@ void RenderWidgetHostViewViews::Destroy() {
   MessageLoop::current()->DeleteSoon(FROM_HERE, this);
 }
 
-void RenderWidgetHostViewViews::SetTooltipText(const std::wstring& tip) {
+void RenderWidgetHostViewViews::SetTooltipText(const string16& tip) {
   const int kMaxTooltipLength = 8 << 10;
   // Clamp the tooltip length to kMaxTooltipLength so that we don't
   // accidentally DOS the user with a mega tooltip.
-  tooltip_text_ =
-      ui::TruncateString(WideToUTF16Hack(tip), kMaxTooltipLength);
+  tooltip_text_ = ui::TruncateString(tip, kMaxTooltipLength);
   if (GetWidget())
     GetWidget()->TooltipTextChanged(this);
 }
@@ -577,10 +576,10 @@ views::TextInputClient* RenderWidgetHostViewViews::GetTextInputClient() {
 }
 
 bool RenderWidgetHostViewViews::GetTooltipText(const gfx::Point& p,
-                                               std::wstring* tooltip) {
+                                               string16* tooltip) {
   if (tooltip_text_.length() == 0)
     return false;
-  *tooltip = UTF16ToWide(tooltip_text_);
+  *tooltip = tooltip_text_;
   return true;
 }
 
diff --git a/chrome/browser/renderer_host/render_widget_host_view_views.h b/chrome/browser/renderer_host/render_widget_host_view_views.h
index e81b48d..0e923c3 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_views.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_views.h
@@ -79,7 +79,7 @@ class RenderWidgetHostViewViews : public RenderWidgetHostView,
   virtual void RenderViewGone(base::TerminationStatus status,
                               int error_code) OVERRIDE;
   virtual void Destroy() OVERRIDE;
-  virtual void SetTooltipText(const std::wstring& tooltip_text) OVERRIDE;
+  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
   virtual void SelectionChanged(const std::string& text,
                                 const ui::Range& range,
                                 const gfx::Point& start,
@@ -140,8 +140,7 @@ class RenderWidgetHostViewViews : public RenderWidgetHostView,
   virtual bool OnKeyReleased(const views::KeyEvent& event) OVERRIDE;
   virtual bool OnMouseWheel(const views::MouseWheelEvent& event) OVERRIDE;
   virtual views::TextInputClient* GetTextInputClient() OVERRIDE;
-  virtual bool GetTooltipText(const gfx::Point& p, std::wstring* tooltip)
-      OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
 
   // Overridden from TextInputClient:
   virtual void SetCompositionText(
diff --git a/chrome/browser/ui/panels/panel_browser_frame_view.cc b/chrome/browser/ui/panels/panel_browser_frame_view.cc
index d713dff..b27e96e 100644
--- a/chrome/browser/ui/panels/panel_browser_frame_view.cc
+++ b/chrome/browser/ui/panels/panel_browser_frame_view.cc
@@ -223,7 +223,7 @@ PanelBrowserFrameView::PanelBrowserFrameView(BrowserFrame* frame,
   settings_button_->set_alignment(views::TextButton::ALIGN_CENTER);
   settings_button_->set_border(NULL);
   settings_button_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_NEW_TAB_APP_SETTINGS)));
+      l10n_util::GetStringUTF16(IDS_NEW_TAB_APP_SETTINGS));
   settings_button_->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_NEW_TAB_APP_SETTINGS));
   settings_button_->SetVisible(is_settings_button_visible_);
@@ -237,7 +237,7 @@ PanelBrowserFrameView::PanelBrowserFrameView(BrowserFrame* frame,
   close_button_->SetImage(views::CustomButton::BS_PUSHED,
                           close_button_resources.pushed_image);
   close_button_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_CLOSE_TAB)));
+      l10n_util::GetStringUTF16(IDS_TOOLTIP_CLOSE_TAB));
   close_button_->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_ACCNAME_CLOSE));
   AddChildView(close_button_);
diff --git a/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc b/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
index 2722199..22c4bf7 100644
--- a/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
+++ b/chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc
@@ -148,11 +148,11 @@ class BookmarkButton : public views::TextButton {
   }
 
   virtual bool GetTooltipText(const gfx::Point& p,
-                              std::wstring* tooltip) OVERRIDE {
+                              string16* tooltip) OVERRIDE {
     gfx::Point location(p);
     ConvertPointToScreen(this, &location);
-    *tooltip = BookmarkBarView::CreateToolTipForURLAndTitle(location, url_,
-        text(), profile_);
+    *tooltip = WideToUTF16Hack(BookmarkBarView::CreateToolTipForURLAndTitle(
+                                   location, url_, text(), profile_));
     return !tooltip->empty();
   }
 
@@ -198,9 +198,9 @@ class BookmarkFolderButton : public views::MenuButton {
   }
 
   virtual bool GetTooltipText(const gfx::Point& p,
-                              std::wstring* tooltip) OVERRIDE {
+                              string16* tooltip) OVERRIDE {
     if (text_size_.width() > GetTextBounds().width())
-      *tooltip = UTF16ToWide(text_);
+      *tooltip = text_;
     return !tooltip->empty();
   }
 
@@ -1250,7 +1250,7 @@ views::TextButton* BookmarkBarView::CreateSyncErrorButton() {
   // The tooltip is the only way we have to display text explaining the error
   // to the user.
   sync_error_button->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_SYNC_BOOKMARK_BAR_ERROR_DESC)));
+      l10n_util::GetStringUTF16(IDS_SYNC_BOOKMARK_BAR_ERROR_DESC));
   sync_error_button->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_ACCNAME_SYNC_ERROR_BUTTON));
   sync_error_button->SetIcon(
diff --git a/chrome/browser/ui/views/bookmarks/bookmark_menu_controller_views.cc b/chrome/browser/ui/views/bookmarks/bookmark_menu_controller_views.cc
index 5658705..6832c7e 100644
--- a/chrome/browser/ui/views/bookmarks/bookmark_menu_controller_views.cc
+++ b/chrome/browser/ui/views/bookmarks/bookmark_menu_controller_views.cc
@@ -83,8 +83,7 @@ void BookmarkMenuController::SetPageNavigator(PageNavigator* navigator) {
   menu_delegate_->SetPageNavigator(navigator);
 }
 
-std::wstring BookmarkMenuController::GetTooltipText(int id,
-                                                    const gfx::Point& p) {
+string16 BookmarkMenuController::GetTooltipText(int id, const gfx::Point& p) {
   return menu_delegate_->GetTooltipText(id, p);
 }
 
diff --git a/chrome/browser/ui/views/bookmarks/bookmark_menu_controller_views.h b/chrome/browser/ui/views/bookmarks/bookmark_menu_controller_views.h
index 4cfda5c..3f0591f 100644
--- a/chrome/browser/ui/views/bookmarks/bookmark_menu_controller_views.h
+++ b/chrome/browser/ui/views/bookmarks/bookmark_menu_controller_views.h
@@ -77,7 +77,7 @@ class BookmarkMenuController : public BaseBookmarkModelObserver,
   void set_observer(Observer* observer) { observer_ = observer; }
 
   // MenuDelegate methods.
-  virtual std::wstring GetTooltipText(int id, const gfx::Point& p);
+  virtual string16 GetTooltipText(int id, const gfx::Point& p) OVERRIDE;
   virtual bool IsTriggerableEvent(views::MenuItemView* view,
                                   const views::MouseEvent& e);
   virtual void ExecuteCommand(int id, int mouse_event_flags);
diff --git a/chrome/browser/ui/views/bookmarks/bookmark_menu_delegate.cc b/chrome/browser/ui/views/bookmarks/bookmark_menu_delegate.cc
index 35073ff..1ec41f4 100644
--- a/chrome/browser/ui/views/bookmarks/bookmark_menu_delegate.cc
+++ b/chrome/browser/ui/views/bookmarks/bookmark_menu_delegate.cc
@@ -95,16 +95,17 @@ void BookmarkMenuDelegate::SetActiveMenu(const BookmarkNode* node,
   menu_ = node_to_menu_map_[node];
 }
 
-std::wstring BookmarkMenuDelegate::GetTooltipText(
-    int id,
-    const gfx::Point& screen_loc) {
+string16 BookmarkMenuDelegate::GetTooltipText(int id,
+                                              const gfx::Point& screen_loc) {
   DCHECK(menu_id_to_node_map_.find(id) != menu_id_to_node_map_.end());
 
   const BookmarkNode* node = menu_id_to_node_map_[id];
-  if (node->is_url())
-    return BookmarkBarView::CreateToolTipForURLAndTitle(
-        screen_loc, node->url(), UTF16ToWide(node->GetTitle()), profile_);
-  return std::wstring();
+  if (node->is_url()) {
+    return WideToUTF16Hack(BookmarkBarView::CreateToolTipForURLAndTitle(
+                               screen_loc, node->url(),
+                               UTF16ToWide(node->GetTitle()), profile_));
+  }
+  return string16();
 }
 
 bool BookmarkMenuDelegate::IsTriggerableEvent(views::MenuItemView* menu,
diff --git a/chrome/browser/ui/views/bookmarks/bookmark_menu_delegate.h b/chrome/browser/ui/views/bookmarks/bookmark_menu_delegate.h
index 134cf29..ef4330d 100644
--- a/chrome/browser/ui/views/bookmarks/bookmark_menu_delegate.h
+++ b/chrome/browser/ui/views/bookmarks/bookmark_menu_delegate.h
@@ -85,7 +85,7 @@ class BookmarkMenuDelegate : public BaseBookmarkModelObserver,
   bool is_mutating_model() const { return is_mutating_model_; }
 
   // MenuDelegate like methods (see class description for details).
-  std::wstring GetTooltipText(int id, const gfx::Point& p);
+  string16 GetTooltipText(int id, const gfx::Point& p);
   bool IsTriggerableEvent(views::MenuItemView* menu,
                           const views::MouseEvent& e);
   void ExecuteCommand(int id, int mouse_event_flags);
diff --git a/chrome/browser/ui/views/browser_actions_container.cc b/chrome/browser/ui/views/browser_actions_container.cc
index f49cb4c..db456de 100644
--- a/chrome/browser/ui/views/browser_actions_container.cc
+++ b/chrome/browser/ui/views/browser_actions_container.cc
@@ -172,7 +172,7 @@ void BrowserActionButton::UpdateState() {
   string16 name = UTF8ToUTF16(browser_action()->GetTitle(tab_id));
   if (name.empty())
     name = UTF8ToUTF16(extension()->name());
-  SetTooltipText(UTF16ToWideHack(name));
+  SetTooltipText(name);
   SetAccessibleName(name);
   parent()->SchedulePaint();
 }
diff --git a/chrome/browser/ui/views/compact_nav/compact_location_bar_view.cc b/chrome/browser/ui/views/compact_nav/compact_location_bar_view.cc
index 98185e8..31aca7f 100644
--- a/chrome/browser/ui/views/compact_nav/compact_location_bar_view.cc
+++ b/chrome/browser/ui/views/compact_nav/compact_location_bar_view.cc
@@ -120,8 +120,7 @@ void CompactLocationBarView::Init() {
   reload_button_->set_triggerable_event_flags(ui::EF_LEFT_BUTTON_DOWN |
       ui::EF_MIDDLE_BUTTON_DOWN);
   reload_button_->set_tag(IDC_RELOAD);
-  reload_button_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_RELOAD)));
+  reload_button_->SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_RELOAD));
   reload_button_->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_ACCNAME_RELOAD));
   reload_button_->set_id(VIEW_ID_RELOAD_BUTTON);
diff --git a/chrome/browser/ui/views/compact_nav/compact_navigation_bar.cc b/chrome/browser/ui/views/compact_nav/compact_navigation_bar.cc
index b161300..adec663 100644
--- a/chrome/browser/ui/views/compact_nav/compact_navigation_bar.cc
+++ b/chrome/browser/ui/views/compact_nav/compact_navigation_bar.cc
@@ -79,8 +79,7 @@ void CompactNavigationBar::Init() {
   back_->set_triggerable_event_flags(ui::EF_LEFT_BUTTON_DOWN |
                                      ui::EF_MIDDLE_BUTTON_DOWN);
   back_->set_tag(IDC_BACK);
-  back_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_BACK)));
+  back_->SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_BACK));
   back_->SetAccessibleName(l10n_util::GetStringUTF16(IDS_ACCNAME_BACK));
   back_->SetImageAlignment(views::ImageButton::ALIGN_CENTER,
                            views::ImageButton::ALIGN_MIDDLE);
@@ -95,8 +94,7 @@ void CompactNavigationBar::Init() {
   forward_->set_triggerable_event_flags(ui::EF_LEFT_BUTTON_DOWN |
                                         ui::EF_MIDDLE_BUTTON_DOWN);
   forward_->set_tag(IDC_FORWARD);
-  forward_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_FORWARD)));
+  forward_->SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_FORWARD));
   forward_->SetAccessibleName(l10n_util::GetStringUTF16((IDS_ACCNAME_FORWARD)));
   forward_->SetImageAlignment(views::ImageButton::ALIGN_CENTER,
                               views::ImageButton::ALIGN_MIDDLE);
diff --git a/chrome/browser/ui/views/compact_nav/compact_options_bar.cc b/chrome/browser/ui/views/compact_nav/compact_options_bar.cc
index 5ba008f..1e2548b 100644
--- a/chrome/browser/ui/views/compact_nav/compact_options_bar.cc
+++ b/chrome/browser/ui/views/compact_nav/compact_options_bar.cc
@@ -46,9 +46,9 @@ void CompactOptionsBar::Init() {
   app_menu_->set_border(NULL);
   app_menu_->EnableCanvasFlippingForRTLUI(true);
   app_menu_->SetAccessibleName(l10n_util::GetStringUTF16(IDS_ACCNAME_APP));
-  app_menu_->SetTooltipText(UTF16ToWide(l10n_util::GetStringFUTF16(
+  app_menu_->SetTooltipText(l10n_util::GetStringFUTF16(
       IDS_APPMENU_TOOLTIP,
-      l10n_util::GetStringUTF16(IDS_PRODUCT_NAME))));
+      l10n_util::GetStringUTF16(IDS_PRODUCT_NAME)));
   app_menu_->set_id(VIEW_ID_APP_MENU);
   AddChildView(app_menu_);
 
diff --git a/chrome/browser/ui/views/default_search_view.cc b/chrome/browser/ui/views/default_search_view.cc
index e54c10d..6f7e30c 100644
--- a/chrome/browser/ui/views/default_search_view.cc
+++ b/chrome/browser/ui/views/default_search_view.cc
@@ -83,7 +83,7 @@ views::View* CreateProviderLogo(
     SkBitmap* logo_bmp =
         ResourceBundle::GetSharedInstance().GetBitmapNamed(logo_id);
     logo_image->SetImage(logo_bmp);
-    logo_image->SetTooltipText(short_name);
+    logo_image->SetTooltipText(WideToUTF16Hack(short_name));
     logo_view = logo_image;
   } else {
     // No logo -- show a text label.
@@ -92,7 +92,7 @@ views::View* CreateProviderLogo(
     logo_label->SetFont(logo_label->font().DeriveFont(3, gfx::Font::BOLD));
     logo_label->SetHorizontalAlignment(views::Label::ALIGN_CENTER);
     // Tooltip text provides accessibility for low-vision users.
-    logo_label->SetTooltipText(short_name);
+    logo_label->SetTooltipText(WideToUTF16Hack(short_name));
     logo_view = logo_label;
   }
 
diff --git a/chrome/browser/ui/views/download/download_item_view.cc b/chrome/browser/ui/views/download/download_item_view.cc
index 58c42d3..02010f7 100644
--- a/chrome/browser/ui/views/download/download_item_view.cc
+++ b/chrome/browser/ui/views/download/download_item_view.cc
@@ -180,8 +180,7 @@ DownloadItemView::DownloadItemView(DownloadItem* download,
   dangerous_mode_body_image_set_ = dangerous_mode_body_image_set;
 
   LoadIcon();
-  tooltip_text_ =
-      UTF16ToWide(download_->GetFileNameToReportUser().LossyDisplayName());
+  tooltip_text_ = download_->GetFileNameToReportUser().LossyDisplayName();
 
   font_ = ResourceBundle::GetSharedInstance().GetFont(ResourceBundle::BaseFont);
   box_height_ = std::max<int>(2 * kVerticalPadding + font_.GetHeight() +
@@ -581,7 +580,7 @@ bool DownloadItemView::OnKeyPressed(const views::KeyEvent& event) {
 }
 
 bool DownloadItemView::GetTooltipText(const gfx::Point& p,
-                                      std::wstring* tooltip) {
+                                      string16* tooltip) {
   if (tooltip_text_.empty())
     return false;
 
@@ -997,8 +996,7 @@ void DownloadItemView::ClearDangerousMode() {
 
   // We need to load the icon now that the download_ has the real path.
   LoadIcon();
-  tooltip_text_ =
-      UTF16ToWide(download_->GetFileNameToReportUser().LossyDisplayName());
+  tooltip_text_ = download_->GetFileNameToReportUser().LossyDisplayName();
 
   // Force the shelf to layout again as our size has changed.
   parent_->Layout();
diff --git a/chrome/browser/ui/views/download/download_item_view.h b/chrome/browser/ui/views/download/download_item_view.h
index f518b12..43c999c 100644
--- a/chrome/browser/ui/views/download/download_item_view.h
+++ b/chrome/browser/ui/views/download/download_item_view.h
@@ -87,8 +87,7 @@ class DownloadItemView : public views::ButtonListener,
   virtual void OnMouseMoved(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseExited(const views::MouseEvent& event) OVERRIDE;
   virtual bool OnKeyPressed(const views::KeyEvent& event) OVERRIDE;
-  virtual bool GetTooltipText(const gfx::Point& p,
-                              std::wstring* tooltip) OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
   virtual void ShowContextMenu(const gfx::Point& p,
                                bool is_mouse_gesture) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
@@ -204,7 +203,7 @@ class DownloadItemView : public views::ButtonListener,
   gfx::Font font_;
 
   // The tooltip.
-  std::wstring tooltip_text_;
+  string16 tooltip_text_;
 
   // The current state (normal, hot or pushed) of the body and drop-down.
   State body_state_;
diff --git a/chrome/browser/ui/views/edit_search_engine_dialog.cc b/chrome/browser/ui/views/edit_search_engine_dialog.cc
index 81cdeb2cf..13e596c 100644
--- a/chrome/browser/ui/views/edit_search_engine_dialog.cc
+++ b/chrome/browser/ui/views/edit_search_engine_dialog.cc
@@ -255,13 +255,12 @@ void EditSearchEngineDialog::UpdateImageView(ImageView* image_view,
                                              bool is_valid,
                                              int invalid_message_id) {
   if (is_valid) {
-    image_view->SetTooltipText(std::wstring());
+    image_view->SetTooltipText(string16());
     image_view->SetImage(
         ResourceBundle::GetSharedInstance().GetBitmapNamed(
             IDR_INPUT_GOOD));
   } else {
-    image_view->SetTooltipText(
-        UTF16ToWide(l10n_util::GetStringUTF16(invalid_message_id)));
+    image_view->SetTooltipText(l10n_util::GetStringUTF16(invalid_message_id)) ;
     image_view->SetImage(
         ResourceBundle::GetSharedInstance().GetBitmapNamed(
             IDR_INPUT_ALERT));
diff --git a/chrome/browser/ui/views/extensions/browser_action_overflow_menu_controller.cc b/chrome/browser/ui/views/extensions/browser_action_overflow_menu_controller.cc
index b1472cf..3cd1a56 100644
--- a/chrome/browser/ui/views/extensions/browser_action_overflow_menu_controller.cc
+++ b/chrome/browser/ui/views/extensions/browser_action_overflow_menu_controller.cc
@@ -45,7 +45,7 @@ BrowserActionOverflowMenuController::BrowserActionOverflowMenuController(
         canvas->AsCanvasSkia()->ExtractBitmap());
 
     // Set the tooltip for this item.
-    std::wstring tooltip = UTF8ToWide(
+    string16 tooltip = UTF8ToUTF16(
         view->button()->extension()->browser_action()->GetTitle(
             owner_->GetCurrentTabId()));
     menu_->SetTooltip(tooltip, command_id);
diff --git a/chrome/browser/ui/views/find_bar_view.cc b/chrome/browser/ui/views/find_bar_view.cc
index 150b218..aba1533 100644
--- a/chrome/browser/ui/views/find_bar_view.cc
+++ b/chrome/browser/ui/views/find_bar_view.cc
@@ -106,8 +106,8 @@ FindBarView::FindBarView(FindBarHost* host)
       rb.GetBitmapNamed(IDR_FINDINPAGE_PREV_H));
   find_previous_button_->SetImage(views::CustomButton::BS_DISABLED,
       rb.GetBitmapNamed(IDR_FINDINPAGE_PREV_P));
-  find_previous_button_->SetTooltipText(UTF16ToWide(
-      l10n_util::GetStringUTF16(IDS_FIND_IN_PAGE_PREVIOUS_TOOLTIP)));
+  find_previous_button_->SetTooltipText(
+      l10n_util::GetStringUTF16(IDS_FIND_IN_PAGE_PREVIOUS_TOOLTIP));
   find_previous_button_->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_ACCNAME_PREVIOUS));
   AddChildView(find_previous_button_);
@@ -122,7 +122,7 @@ FindBarView::FindBarView(FindBarHost* host)
   find_next_button_->SetImage(views::CustomButton::BS_DISABLED,
       rb.GetBitmapNamed(IDR_FINDINPAGE_NEXT_P));
   find_next_button_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_FIND_IN_PAGE_NEXT_TOOLTIP)));
+      l10n_util::GetStringUTF16(IDS_FIND_IN_PAGE_NEXT_TOOLTIP));
   find_next_button_->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_ACCNAME_NEXT));
   AddChildView(find_next_button_);
@@ -137,7 +137,7 @@ FindBarView::FindBarView(FindBarHost* host)
   close_button_->SetImage(views::CustomButton::BS_PUSHED,
                           rb.GetBitmapNamed(IDR_CLOSE_BAR_P));
   close_button_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_FIND_IN_PAGE_CLOSE_TOOLTIP)));
+      l10n_util::GetStringUTF16(IDS_FIND_IN_PAGE_CLOSE_TOOLTIP));
   close_button_->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_ACCNAME_CLOSE));
   AddChildView(close_button_);
diff --git a/chrome/browser/ui/views/first_run_search_engine_view.cc b/chrome/browser/ui/views/first_run_search_engine_view.cc
index 7163e67..7112f4b 100644
--- a/chrome/browser/ui/views/first_run_search_engine_view.cc
+++ b/chrome/browser/ui/views/first_run_search_engine_view.cc
@@ -100,7 +100,7 @@ SearchEngineChoice::SearchEngineChoice(views::ButtonListener* listener,
     if (use_small_logos)
       logo_image->SetImageSize(gfx::Size(kSmallLogoWidth, kSmallLogoHeight));
     // Tooltip text provides accessibility for low-vision users.
-    logo_image->SetTooltipText(search_engine_->short_name());
+    logo_image->SetTooltipText(WideToUTF16Hack(search_engine_->short_name()));
     choice_view_ = logo_image;
   } else {
     // No logo -- we must show a text label.
@@ -108,7 +108,7 @@ SearchEngineChoice::SearchEngineChoice(views::ButtonListener* listener,
     logo_label->SetColor(SK_ColorDKGRAY);
     logo_label->SetFont(logo_label->font().DeriveFont(3, gfx::Font::BOLD));
     logo_label->SetHorizontalAlignment(views::Label::ALIGN_CENTER);
-    logo_label->SetTooltipText(search_engine_->short_name());
+    logo_label->SetTooltipText(WideToUTF16Hack(search_engine_->short_name()));
     logo_label->SetMultiLine(true);
     logo_label->SizeToFit(kSmallLogoWidth);
     choice_view_ = logo_label;
diff --git a/chrome/browser/ui/views/location_bar/content_setting_image_view.cc b/chrome/browser/ui/views/location_bar/content_setting_image_view.cc
index 990323f..4eca62a 100644
--- a/chrome/browser/ui/views/location_bar/content_setting_image_view.cc
+++ b/chrome/browser/ui/views/location_bar/content_setting_image_view.cc
@@ -72,7 +72,7 @@ void ContentSettingImageView::UpdateFromTabContents(TabContents* tab_contents) {
   }
   SetImage(ResourceBundle::GetSharedInstance().GetBitmapNamed(
       content_setting_image_model_->get_icon()));
-  SetTooltipText(UTF8ToWide(content_setting_image_model_->get_tooltip()));
+  SetTooltipText(UTF8ToUTF16(content_setting_image_model_->get_tooltip()));
   SetVisible(true);
 
   TabSpecificContentSettings* content_settings = NULL;
diff --git a/chrome/browser/ui/views/location_bar/location_icon_view.cc b/chrome/browser/ui/views/location_bar/location_icon_view.cc
index 2846337..2755501 100644
--- a/chrome/browser/ui/views/location_bar/location_icon_view.cc
+++ b/chrome/browser/ui/views/location_bar/location_icon_view.cc
@@ -10,8 +10,7 @@
 
 LocationIconView::LocationIconView(LocationBarView* location_bar)
     : ALLOW_THIS_IN_INITIALIZER_LIST(click_handler_(this, location_bar)) {
-  SetTooltipText(UTF16ToWide(l10n_util::GetStringUTF16(
-      IDS_TOOLTIP_LOCATION_ICON)));
+  SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_LOCATION_ICON));
 }
 
 LocationIconView::~LocationIconView() {
@@ -29,9 +28,8 @@ void LocationIconView::OnMouseReleased(const views::MouseEvent& event) {
 
 void LocationIconView::ShowTooltip(bool show) {
   if (show) {
-    SetTooltipText(UTF16ToWide(l10n_util::GetStringUTF16(
-            IDS_TOOLTIP_LOCATION_ICON)));
+    SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_LOCATION_ICON));
   } else {
-    SetTooltipText(L"");
+    SetTooltipText(string16());
   }
 }
diff --git a/chrome/browser/ui/views/location_bar/page_action_image_view.cc b/chrome/browser/ui/views/location_bar/page_action_image_view.cc
index 0638fa6..a7fa6f0 100644
--- a/chrome/browser/ui/views/location_bar/page_action_image_view.cc
+++ b/chrome/browser/ui/views/location_bar/page_action_image_view.cc
@@ -193,7 +193,7 @@ void PageActionImageView::UpdateVisibility(TabContents* contents,
 
   // Set the tooltip.
   tooltip_ = page_action_->GetTitle(current_tab_id_);
-  SetTooltipText(UTF8ToWide(tooltip_));
+  SetTooltipText(UTF8ToUTF16(tooltip_));
 
   // Set the image.
   // It can come from three places. In descending order of priority:
diff --git a/chrome/browser/ui/views/location_bar/star_view.cc b/chrome/browser/ui/views/location_bar/star_view.cc
index 6e1b91e..8d4c0c0 100644
--- a/chrome/browser/ui/views/location_bar/star_view.cc
+++ b/chrome/browser/ui/views/location_bar/star_view.cc
@@ -27,8 +27,8 @@ StarView::~StarView() {
 }
 
 void StarView::SetToggled(bool on) {
-  SetTooltipText(UTF16ToWide(l10n_util::GetStringUTF16(
-      on ? IDS_TOOLTIP_STARRED : IDS_TOOLTIP_STAR)));
+  SetTooltipText(l10n_util::GetStringUTF16(
+      on ? IDS_TOOLTIP_STARRED : IDS_TOOLTIP_STAR));
   SetImage(ResourceBundle::GetSharedInstance().GetBitmapNamed(
       on ? IDR_STAR_LIT : IDR_STAR));
 }
@@ -38,7 +38,7 @@ void StarView::GetAccessibleState(ui::AccessibleViewState* state) {
   state->role = ui::AccessibilityTypes::ROLE_PUSHBUTTON;
 }
 
-bool StarView::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+bool StarView::GetTooltipText(const gfx::Point& p, string16* tooltip) {
   // Don't show tooltip to distract user if BookmarkBubbleView is showing.
   if (browser::IsBookmarkBubbleViewShowing())
     return false;
diff --git a/chrome/browser/ui/views/location_bar/star_view.h b/chrome/browser/ui/views/location_bar/star_view.h
index 0ef704d..319936e 100644
--- a/chrome/browser/ui/views/location_bar/star_view.h
+++ b/chrome/browser/ui/views/location_bar/star_view.h
@@ -28,8 +28,7 @@ class StarView : public views::ImageView, public BubbleDelegate {
  private:
   // views::ImageView overrides:
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
-  virtual bool GetTooltipText(const gfx::Point& p,
-                              std::wstring* tooltip) OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
   virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseReleased(const views::MouseEvent& event) OVERRIDE;
   virtual bool OnKeyPressed(const views::KeyEvent& event) OVERRIDE;
diff --git a/chrome/browser/ui/views/notifications/balloon_view.cc b/chrome/browser/ui/views/notifications/balloon_view.cc
index 6067b42..62f3f31 100644
--- a/chrome/browser/ui/views/notifications/balloon_view.cc
+++ b/chrome/browser/ui/views/notifications/balloon_view.cc
@@ -290,8 +290,8 @@ void BalloonViewImpl::Show(Balloon* balloon) {
   options_menu_button_ = new views::MenuButton(NULL, L"", this, false);
   AddChildView(options_menu_button_);
   close_button_ = new views::ImageButton(this);
-  close_button_->SetTooltipText(UTF16ToWide(l10n_util::GetStringUTF16(
-      IDS_NOTIFICATION_BALLOON_DISMISS_LABEL)));
+  close_button_->SetTooltipText(l10n_util::GetStringUTF16(
+      IDS_NOTIFICATION_BALLOON_DISMISS_LABEL));
   AddChildView(close_button_);
 
   // We have to create two windows: one for the contents and one for the
diff --git a/chrome/browser/ui/views/reload_button.cc b/chrome/browser/ui/views/reload_button.cc
index db95490..1fb81f4 100644
--- a/chrome/browser/ui/views/reload_button.cc
+++ b/chrome/browser/ui/views/reload_button.cc
@@ -124,10 +124,10 @@ void ReloadButton::OnMouseExited(const views::MouseEvent& event) {
     SetState(BS_NORMAL);
 }
 
-bool ReloadButton::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+bool ReloadButton::GetTooltipText(const gfx::Point& p, string16* tooltip) {
   int text_id = visible_mode_ == MODE_RELOAD ? IDS_TOOLTIP_RELOAD
                                              : IDS_TOOLTIP_STOP;
-  tooltip->assign(UTF16ToWide(l10n_util::GetStringUTF16(text_id)));
+  tooltip->assign(l10n_util::GetStringUTF16(text_id));
   return true;
 }
 
diff --git a/chrome/browser/ui/views/reload_button.h b/chrome/browser/ui/views/reload_button.h
index e7cd856..4b0cdc2 100644
--- a/chrome/browser/ui/views/reload_button.h
+++ b/chrome/browser/ui/views/reload_button.h
@@ -46,8 +46,7 @@ class ReloadButton : public views::ToggleImageButton,
 
   // Overridden from views::View:
   virtual void OnMouseExited(const views::MouseEvent& event) OVERRIDE;
-  virtual bool GetTooltipText(const gfx::Point& p,
-                              std::wstring* tooltip) OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
   virtual std::string GetClassName() const OVERRIDE;
 
  private:
diff --git a/chrome/browser/ui/views/tabs/base_tab.cc b/chrome/browser/ui/views/tabs/base_tab.cc
index cd5f249..4be5f54 100644
--- a/chrome/browser/ui/views/tabs/base_tab.cc
+++ b/chrome/browser/ui/views/tabs/base_tab.cc
@@ -165,7 +165,7 @@ BaseTab::BaseTab(TabController* controller)
   close_button_->SetImage(views::CustomButton::BS_PUSHED,
                           rb.GetBitmapNamed(IDR_TAB_CLOSE_P));
   close_button_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_CLOSE_TAB)));
+      l10n_util::GetStringUTF16(IDS_TOOLTIP_CLOSE_TAB));
   close_button_->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_ACCNAME_CLOSE));
   // Disable animation so that the red danger sign shows up immediately
@@ -370,13 +370,13 @@ void BaseTab::OnMouseExited(const views::MouseEvent& event) {
   hover_animation_->Hide();
 }
 
-bool BaseTab::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+bool BaseTab::GetTooltipText(const gfx::Point& p, string16* tooltip) {
   if (data_.title.empty())
     return false;
 
   // Only show the tooltip if the title is truncated.
   if (font_->GetStringWidth(data_.title) > GetTitleBounds().width()) {
-    *tooltip = UTF16ToWide(data_.title);
+    *tooltip = data_.title;
     return true;
   }
   return false;
diff --git a/chrome/browser/ui/views/tabs/base_tab.h b/chrome/browser/ui/views/tabs/base_tab.h
index 42a00ad..5157eb6 100644
--- a/chrome/browser/ui/views/tabs/base_tab.h
+++ b/chrome/browser/ui/views/tabs/base_tab.h
@@ -91,8 +91,7 @@ class BaseTab : public ui::AnimationDelegate,
   virtual void OnMouseCaptureLost() OVERRIDE;
   virtual void OnMouseEntered(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseExited(const views::MouseEvent& event) OVERRIDE;
-  virtual bool GetTooltipText(const gfx::Point& p,
-                              std::wstring* tooltip) OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
  protected:
diff --git a/chrome/browser/ui/views/toolbar_view.cc b/chrome/browser/ui/views/toolbar_view.cc
index 2d62750..ba30929 100644
--- a/chrome/browser/ui/views/toolbar_view.cc
+++ b/chrome/browser/ui/views/toolbar_view.cc
@@ -132,8 +132,7 @@ void ToolbarView::Init() {
   back_->set_tag(IDC_BACK);
   back_->SetImageAlignment(views::ImageButton::ALIGN_RIGHT,
                            views::ImageButton::ALIGN_TOP);
-  back_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_BACK)));
+  back_->SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_BACK));
   back_->SetAccessibleName(l10n_util::GetStringUTF16(IDS_ACCNAME_BACK));
   back_->set_id(VIEW_ID_BACK_BUTTON);
 
@@ -141,8 +140,7 @@ void ToolbarView::Init() {
   forward_->set_triggerable_event_flags(ui::EF_LEFT_BUTTON_DOWN |
                                         ui::EF_MIDDLE_BUTTON_DOWN);
   forward_->set_tag(IDC_FORWARD);
-  forward_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_FORWARD)));
+  forward_->SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_FORWARD));
   forward_->SetAccessibleName(l10n_util::GetStringUTF16(IDS_ACCNAME_FORWARD));
   forward_->set_id(VIEW_ID_FORWARD_BUTTON);
 
@@ -155,8 +153,7 @@ void ToolbarView::Init() {
   reload_->set_triggerable_event_flags(ui::EF_LEFT_BUTTON_DOWN |
                                        ui::EF_MIDDLE_BUTTON_DOWN);
   reload_->set_tag(IDC_RELOAD);
-  reload_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_RELOAD)));
+  reload_->SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_RELOAD));
   reload_->SetAccessibleName(l10n_util::GetStringUTF16(IDS_ACCNAME_RELOAD));
   reload_->set_id(VIEW_ID_RELOAD_BUTTON);
 
@@ -164,8 +161,7 @@ void ToolbarView::Init() {
   home_->set_triggerable_event_flags(ui::EF_LEFT_BUTTON_DOWN |
                                      ui::EF_MIDDLE_BUTTON_DOWN);
   home_->set_tag(IDC_HOME);
-  home_->SetTooltipText(
-      UTF16ToWide(l10n_util::GetStringUTF16(IDS_TOOLTIP_HOME)));
+  home_->SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_HOME));
   home_->SetAccessibleName(l10n_util::GetStringUTF16(IDS_ACCNAME_HOME));
   home_->set_id(VIEW_ID_HOME_BUTTON);
 
@@ -179,9 +175,9 @@ void ToolbarView::Init() {
   app_menu_->set_border(NULL);
   app_menu_->EnableCanvasFlippingForRTLUI(true);
   app_menu_->SetAccessibleName(l10n_util::GetStringUTF16(IDS_ACCNAME_APP));
-  app_menu_->SetTooltipText(UTF16ToWide(l10n_util::GetStringFUTF16(
+  app_menu_->SetTooltipText(l10n_util::GetStringFUTF16(
       IDS_APPMENU_TOOLTIP,
-      l10n_util::GetStringUTF16(IDS_PRODUCT_NAME))));
+      l10n_util::GetStringUTF16(IDS_PRODUCT_NAME)));
   app_menu_->set_id(VIEW_ID_APP_MENU);
 
   // Add any necessary badges to the menu item based on the system state.
@@ -207,9 +203,9 @@ void ToolbarView::Init() {
   // Accessibility specific tooltip text.
   if (BrowserAccessibilityState::GetInstance()->IsAccessibleBrowser()) {
     back_->SetTooltipText(
-        UTF16ToWide(l10n_util::GetStringUTF16(IDS_ACCNAME_TOOLTIP_BACK)));
+        l10n_util::GetStringUTF16(IDS_ACCNAME_TOOLTIP_BACK));
     forward_->SetTooltipText(
-        UTF16ToWide(l10n_util::GetStringUTF16(IDS_ACCNAME_TOOLTIP_FORWARD)));
+        l10n_util::GetStringUTF16(IDS_ACCNAME_TOOLTIP_FORWARD));
   }
 }
 
diff --git a/chrome/browser/ui/views/wrench_menu.cc b/chrome/browser/ui/views/wrench_menu.cc
index f688d40..3c3c20c 100644
--- a/chrome/browser/ui/views/wrench_menu.cc
+++ b/chrome/browser/ui/views/wrench_menu.cc
@@ -607,10 +607,10 @@ void WrenchMenu::RunMenu(views::MenuButton* host) {
     selected_menu_model_->ActivatedAt(selected_index_);
 }
 
-std::wstring WrenchMenu::GetTooltipText(int id,
+string16 WrenchMenu::GetTooltipText(int id,
                                         const gfx::Point& p) {
   return is_bookmark_command(id) ?
-      bookmark_menu_delegate_->GetTooltipText(id, p) : std::wstring();
+      bookmark_menu_delegate_->GetTooltipText(id, p) : string16();
 }
 
 bool WrenchMenu::IsTriggerableEvent(views::MenuItemView* menu,
diff --git a/chrome/browser/ui/views/wrench_menu.h b/chrome/browser/ui/views/wrench_menu.h
index c18c5f0..231f379 100644
--- a/chrome/browser/ui/views/wrench_menu.h
+++ b/chrome/browser/ui/views/wrench_menu.h
@@ -37,7 +37,7 @@ class WrenchMenu : public views::MenuDelegate,
   void RunMenu(views::MenuButton* host);
 
   // MenuDelegate overrides:
-  virtual std::wstring GetTooltipText(int id, const gfx::Point& p) OVERRIDE;
+  virtual string16 GetTooltipText(int id, const gfx::Point& p) OVERRIDE;
   virtual bool IsTriggerableEvent(views::MenuItemView* menu,
                                   const views::MouseEvent& e) OVERRIDE;
   virtual bool GetDropFormats(
diff --git a/content/browser/renderer_host/render_widget_host.cc b/content/browser/renderer_host/render_widget_host.cc
index e370fe4..add827a 100644
--- a/content/browser/renderer_host/render_widget_host.cc
+++ b/content/browser/renderer_host/render_widget_host.cc
@@ -854,7 +854,7 @@ void RenderWidgetHost::OnMsgSetTooltipText(
     }
   }
   if (view())
-    view()->SetTooltipText(UTF16ToWide(wrapped_tooltip_text));
+    view()->SetTooltipText(wrapped_tooltip_text);
 }
 
 void RenderWidgetHost::OnMsgRequestMove(const gfx::Rect& pos) {
diff --git a/content/browser/renderer_host/render_widget_host_view.h b/content/browser/renderer_host/render_widget_host_view.h
index 08b500f..8fa8448 100644
--- a/content/browser/renderer_host/render_widget_host_view.h
+++ b/content/browser/renderer_host/render_widget_host_view.h
@@ -181,7 +181,7 @@ class RenderWidgetHostView {
 
   // Tells the View that the tooltip text for the current mouse position over
   // the page has changed.
-  virtual void SetTooltipText(const std::wstring& tooltip_text) = 0;
+  virtual void SetTooltipText(const string16& tooltip_text) = 0;
 
   // Notifies the View that the renderer text selection has changed. |start|
   // and |end| are the visual end points of the selection in the coordinate
diff --git a/content/browser/renderer_host/render_widget_host_view_gtk.cc b/content/browser/renderer_host/render_widget_host_view_gtk.cc
index 4c535f63..d258aac 100644
--- a/content/browser/renderer_host/render_widget_host_view_gtk.cc
+++ b/content/browser/renderer_host/render_widget_host_view_gtk.cc
@@ -819,7 +819,7 @@ void RenderWidgetHostViewGtk::Destroy() {
   MessageLoop::current()->DeleteSoon(FROM_HERE, this);
 }
 
-void RenderWidgetHostViewGtk::SetTooltipText(const std::wstring& tooltip_text) {
+void RenderWidgetHostViewGtk::SetTooltipText(const string16& tooltip_text) {
   // Maximum number of characters we allow in a tooltip.
   const int kMaxTooltipLength = 8 << 10;
   // Clamp the tooltip length to kMaxTooltipLength so that we don't
@@ -827,8 +827,7 @@ void RenderWidgetHostViewGtk::SetTooltipText(const std::wstring& tooltip_text) {
   // this itself).
   // I filed https://bugzilla.gnome.org/show_bug.cgi?id=604641 upstream.
   const string16 clamped_tooltip =
-      ui::TruncateString(WideToUTF16Hack(tooltip_text),
-                         kMaxTooltipLength);
+      ui::TruncateString(tooltip_text, kMaxTooltipLength);
 
   if (clamped_tooltip.empty()) {
     gtk_widget_set_has_tooltip(view_.get(), FALSE);
@@ -836,7 +835,7 @@ void RenderWidgetHostViewGtk::SetTooltipText(const std::wstring& tooltip_text) {
     gtk_widget_set_tooltip_text(view_.get(),
                                 UTF16ToUTF8(clamped_tooltip).c_str());
 #if defined(OS_CHROMEOS)
-    tooltip_window_->SetTooltipText(UTF16ToWideHack(clamped_tooltip));
+    tooltip_window_->SetTooltipText(clamped_tooltip);
 #endif  // defined(OS_CHROMEOS)
   }
 }
diff --git a/content/browser/renderer_host/render_widget_host_view_gtk.h b/content/browser/renderer_host/render_widget_host_view_gtk.h
index 43973f7..5eb9ed4 100644
--- a/content/browser/renderer_host/render_widget_host_view_gtk.h
+++ b/content/browser/renderer_host/render_widget_host_view_gtk.h
@@ -84,7 +84,7 @@ class RenderWidgetHostViewGtk : public RenderWidgetHostView,
                               int error_code) OVERRIDE;
   virtual void Destroy() OVERRIDE;
   virtual void WillDestroyRenderWidget(RenderWidgetHost* rwh) {}
-  virtual void SetTooltipText(const std::wstring& tooltip_text) OVERRIDE;
+  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
   virtual void SelectionChanged(const std::string& text,
                                 const ui::Range& range,
                                 const gfx::Point& start,
diff --git a/content/browser/renderer_host/render_widget_host_view_win.cc b/content/browser/renderer_host/render_widget_host_view_win.cc
index 5003006..f9da032 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.cc
+++ b/content/browser/renderer_host/render_widget_host_view_win.cc
@@ -727,11 +727,11 @@ void RenderWidgetHostViewWin::Destroy() {
   DestroyWindow();
 }
 
-void RenderWidgetHostViewWin::SetTooltipText(const std::wstring& tooltip_text) {
+void RenderWidgetHostViewWin::SetTooltipText(const string16& tooltip_text) {
   // Clamp the tooltip length to kMaxTooltipLength so that we don't
   // accidentally DOS the user with a mega tooltip (since Windows doesn't seem
   // to do this itself).
-  const std::wstring& new_tooltip_text =
+  const string16 new_tooltip_text =
       ui::TruncateString(tooltip_text, kMaxTooltipLength);
 
   if (new_tooltip_text != tooltip_text_) {
@@ -1096,7 +1096,7 @@ LRESULT RenderWidgetHostViewWin::OnNotify(int w_param, NMHDR* header) {
     case TTN_GETDISPINFO: {
       NMTTDISPINFOW* tooltip_info = reinterpret_cast<NMTTDISPINFOW*>(header);
       tooltip_info->szText[0] = L'\0';
-      tooltip_info->lpszText = const_cast<wchar_t*>(tooltip_text_.c_str());
+      tooltip_info->lpszText = const_cast<WCHAR*>(tooltip_text_.c_str());
       ::SendMessage(
         tooltip_hwnd_, TTM_SETMAXTIPWIDTH, 0, kTooltipMaxWidthPixels);
       SetMsgHandled(TRUE);
diff --git a/content/browser/renderer_host/render_widget_host_view_win.h b/content/browser/renderer_host/render_widget_host_view_win.h
index a1656a6..d2047f3 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.h
+++ b/content/browser/renderer_host/render_widget_host_view_win.h
@@ -164,7 +164,7 @@ class RenderWidgetHostViewWin
   // called by TabContents before DestroyWindow
   virtual void WillWmDestroy() OVERRIDE;
   virtual void Destroy() OVERRIDE;
-  virtual void SetTooltipText(const std::wstring& tooltip_text) OVERRIDE;
+  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
   virtual BackingStore* AllocBackingStore(const gfx::Size& size) OVERRIDE;
   virtual void SetBackground(const SkBitmap& background) OVERRIDE;
   virtual void SetVisuallyDeemphasized(const SkColor* color,
@@ -341,7 +341,7 @@ class RenderWidgetHostViewWin
 
   // Tooltips
   // The text to be shown in the tooltip, supplied by the renderer.
-  std::wstring tooltip_text_;
+  string16 tooltip_text_;
   // The tooltip control hwnd
   HWND tooltip_hwnd_;
   // Whether or not a tooltip is currently visible. We use this to track
diff --git a/content/browser/renderer_host/test_render_view_host.h b/content/browser/renderer_host/test_render_view_host.h
index 8c66291..3fdcee1 100644
--- a/content/browser/renderer_host/test_render_view_host.h
+++ b/content/browser/renderer_host/test_render_view_host.h
@@ -87,7 +87,7 @@ class TestRenderWidgetHostView : public RenderWidgetHostView {
                               int error_code) OVERRIDE;
   virtual void WillDestroyRenderWidget(RenderWidgetHost* rwh) { }
   virtual void Destroy() OVERRIDE {}
-  virtual void SetTooltipText(const std::wstring& tooltip_text) OVERRIDE {}
+  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE {}
   virtual BackingStore* AllocBackingStore(const gfx::Size& size) OVERRIDE;
 #if defined(OS_MACOSX)
   virtual void SetTakesFocusOnlyOnMouseDown(bool flag) OVERRIDE {}
diff --git a/ui/base/gtk/tooltip_window_gtk.cc b/ui/base/gtk/tooltip_window_gtk.cc
index 652b0ce..0a5900f 100644
--- a/ui/base/gtk/tooltip_window_gtk.cc
+++ b/ui/base/gtk/tooltip_window_gtk.cc
@@ -23,10 +23,8 @@ TooltipWindowGtk::~TooltipWindowGtk() {
     gtk_widget_destroy(window_);
 }
 
-void TooltipWindowGtk::SetTooltipText(const std::wstring& text) {
-  const std::string& utf8 = WideToUTF8(text);
-
-  gtk_label_set_text(label(), utf8.c_str());
+void TooltipWindowGtk::SetTooltipText(const string16& text) {
+  gtk_label_set_text(label(), UTF16ToUTF8(text).c_str());
 }
 
 GtkLabel* TooltipWindowGtk::label() {
diff --git a/ui/base/gtk/tooltip_window_gtk.h b/ui/base/gtk/tooltip_window_gtk.h
index cffda40..52622a7 100644
--- a/ui/base/gtk/tooltip_window_gtk.h
+++ b/ui/base/gtk/tooltip_window_gtk.h
@@ -8,7 +8,7 @@
 
 #include <string>
 
-#include "base/basictypes.h"
+#include "base/string16.h"
 #include "ui/base/gtk/gtk_integers.h"
 #include "ui/base/gtk/gtk_signal.h"
 #include "ui/base/ui_export.h"
@@ -29,7 +29,7 @@ class UI_EXPORT TooltipWindowGtk {
   virtual ~TooltipWindowGtk();
 
   // Sets tooltip text to display.
-  void SetTooltipText(const std::wstring& text);
+  void SetTooltipText(const string16& text);
 
   GtkLabel* label();
 
diff --git a/views/accessibility/native_view_accessibility_win.cc b/views/accessibility/native_view_accessibility_win.cc
index 347c5e8..d9cdaac 100644
--- a/views/accessibility/native_view_accessibility_win.cc
+++ b/views/accessibility/native_view_accessibility_win.cc
@@ -280,7 +280,7 @@ STDMETHODIMP NativeViewAccessibilityWin::get_accDescription(
   if (!view_)
     return E_FAIL;
 
-  std::wstring temp_desc;
+  string16 temp_desc;
 
   view_->GetTooltipText(gfx::Point(), &temp_desc);
   if (!temp_desc.empty()) {
diff --git a/views/controls/button/button.cc b/views/controls/button/button.cc
index 6d18204..e9f7e2b 100644
--- a/views/controls/button/button.cc
+++ b/views/controls/button/button.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -15,8 +15,8 @@ namespace views {
 Button::~Button() {
 }
 
-void Button::SetTooltipText(const std::wstring& tooltip_text) {
-  tooltip_text_ = WideToUTF16Hack(tooltip_text);
+void Button::SetTooltipText(const string16& tooltip_text) {
+  tooltip_text_ = tooltip_text;
   TooltipTextChanged();
 }
 
@@ -31,11 +31,11 @@ void Button::SetAccessibleKeyboardShortcut(const string16& shortcut) {
 ////////////////////////////////////////////////////////////////////////////////
 // Button, View overrides:
 
-bool Button::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+bool Button::GetTooltipText(const gfx::Point& p, string16* tooltip) {
   if (tooltip_text_.empty())
     return false;
 
-  *tooltip = UTF16ToWideHack(tooltip_text_);
+  *tooltip = tooltip_text_;
   return true;
 }
 
diff --git a/views/controls/button/button.h b/views/controls/button/button.h
index dde56c1..f1f1a10 100644
--- a/views/controls/button/button.h
+++ b/views/controls/button/button.h
@@ -29,7 +29,7 @@ class VIEWS_EXPORT Button : public View {
  public:
   virtual ~Button();
 
-  void SetTooltipText(const std::wstring& tooltip_text);
+  void SetTooltipText(const string16& tooltip_text);
 
   int tag() const { return tag_; }
   void set_tag(int tag) { tag_ = tag; }
@@ -40,8 +40,7 @@ class VIEWS_EXPORT Button : public View {
   void SetAccessibleKeyboardShortcut(const string16& shortcut);
 
   // Overridden from View:
-  virtual bool GetTooltipText(const gfx::Point& p,
-                              std::wstring* tooltip) OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
  protected:
diff --git a/views/controls/button/image_button.cc b/views/controls/button/image_button.cc
index 612ce88..76ed12c 100644
--- a/views/controls/button/image_button.cc
+++ b/views/controls/button/image_button.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -141,8 +141,8 @@ void ToggleImageButton::SetToggledImage(ButtonState state,
   }
 }
 
-void ToggleImageButton::SetToggledTooltipText(const std::wstring& tooltip) {
-  toggled_tooltip_text_ = WideToUTF16Hack(tooltip);
+void ToggleImageButton::SetToggledTooltipText(const string16& tooltip) {
+  toggled_tooltip_text_ = tooltip;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -163,11 +163,11 @@ void ToggleImageButton::SetImage(ButtonState state, const SkBitmap* image) {
 // ToggleImageButton, View overrides:
 
 bool ToggleImageButton::GetTooltipText(const gfx::Point& p,
-                                       std::wstring* tooltip) {
+                                       string16* tooltip) {
   if (!toggled_ || toggled_tooltip_text_.empty())
     return Button::GetTooltipText(p, tooltip);
 
-  *tooltip = UTF16ToWideHack(toggled_tooltip_text_);
+  *tooltip = toggled_tooltip_text_;
   return true;
 }
 
diff --git a/views/controls/button/image_button.h b/views/controls/button/image_button.h
index 95f4b47..0dc3ab4 100644
--- a/views/controls/button/image_button.h
+++ b/views/controls/button/image_button.h
@@ -93,13 +93,13 @@ class VIEWS_EXPORT ToggleImageButton : public ImageButton {
   void SetToggledImage(ButtonState state, const SkBitmap* image);
 
   // Set the tooltip text displayed when the button is toggled.
-  void SetToggledTooltipText(const std::wstring& tooltip);
+  void SetToggledTooltipText(const string16& tooltip);
 
   // Overridden from ImageButton:
   virtual void SetImage(ButtonState aState, const SkBitmap* anImage);
 
   // Overridden from View:
-  virtual bool GetTooltipText(const gfx::Point& p, std::wstring* tooltip);
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip);
 
  private:
   // The parent class's images_ member is used for the current images,
diff --git a/views/controls/image_view.cc b/views/controls/image_view.cc
index 67f9190b..c0dcad3 100644
--- a/views/controls/image_view.cc
+++ b/views/controls/image_view.cc
@@ -155,15 +155,15 @@ ImageView::Alignment ImageView::GetVerticalAlignment() {
   return vert_alignment_;
 }
 
-void ImageView::SetTooltipText(const std::wstring& tooltip) {
-  tooltip_text_ = WideToUTF16Hack(tooltip);
+void ImageView::SetTooltipText(const string16& tooltip) {
+  tooltip_text_ = tooltip;
 }
 
-std::wstring ImageView::GetTooltipText() {
-  return UTF16ToWideHack(tooltip_text_);
+string16 ImageView::GetTooltipText() {
+  return tooltip_text_;
 }
 
-bool ImageView::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+bool ImageView::GetTooltipText(const gfx::Point& p, string16* tooltip) {
   if (tooltip_text_.empty())
     return false;
 
diff --git a/views/controls/image_view.h b/views/controls/image_view.h
index 7a346b3..2bd4a92 100644
--- a/views/controls/image_view.h
+++ b/views/controls/image_view.h
@@ -71,15 +71,14 @@ class VIEWS_EXPORT ImageView : public View {
   Alignment GetVerticalAlignment();
 
   // Set / Get the tooltip text.
-  void SetTooltipText(const std::wstring& tooltip);
-  std::wstring GetTooltipText();
+  void SetTooltipText(const string16& tooltip);
+  string16 GetTooltipText();
 
   // Overriden from View
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
-  virtual bool GetTooltipText(const gfx::Point& p, std::wstring* tooltip)
-      OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
 
  private:
   // Compute the image origin given the desired size and the receiver alignment
diff --git a/views/controls/label.cc b/views/controls/label.cc
index 54978ec..e61c6e1 100644
--- a/views/controls/label.cc
+++ b/views/controls/label.cc
@@ -129,8 +129,8 @@ void Label::SetElideInMiddle(bool elide_in_middle) {
   }
 }
 
-void Label::SetTooltipText(const std::wstring& tooltip_text) {
-  tooltip_text_ = WideToUTF16Hack(tooltip_text);
+void Label::SetTooltipText(const string16& tooltip_text) {
+  tooltip_text_ = tooltip_text;
 }
 
 void Label::SetMouseOverBackground(Background* background) {
@@ -234,19 +234,19 @@ void Label::OnMouseExited(const MouseEvent& event) {
   SetContainsMouse(false);
 }
 
-bool Label::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+bool Label::GetTooltipText(const gfx::Point& p, string16* tooltip) {
   DCHECK(tooltip);
 
   // If a tooltip has been explicitly set, use it.
   if (!tooltip_text_.empty()) {
-    tooltip->assign(UTF16ToWideHack(tooltip_text_));
+    tooltip->assign(tooltip_text_);
     return true;
   }
 
   // Show the full text if the text does not fit.
   if (!is_multi_line_ &&
       (font_.GetStringWidth(text_) > GetAvailableRect().width())) {
-    *tooltip = UTF16ToWideHack(text_);
+    *tooltip = text_;
     return true;
   }
   return false;
diff --git a/views/controls/label.h b/views/controls/label.h
index 51aa553..8bca9dd 100644
--- a/views/controls/label.h
+++ b/views/controls/label.h
@@ -124,7 +124,7 @@ class VIEWS_EXPORT Label : public View {
   // show the full text if it is wider than its bounds.  Calling this overrides
   // the default behavior and lets you set a custom tooltip.  To revert to
   // default behavior, call this with an empty string.
-  void SetTooltipText(const std::wstring& tooltip_text);
+  void SetTooltipText(const string16& tooltip_text);
 
   // The background color to use when the mouse is over the label. Label
   // takes ownership of the Background.
@@ -171,12 +171,13 @@ class VIEWS_EXPORT Label : public View {
   virtual void OnMouseMoved(const MouseEvent& event) OVERRIDE;
   virtual void OnMouseEntered(const MouseEvent& event) OVERRIDE;
   virtual void OnMouseExited(const MouseEvent& event) OVERRIDE;
+  virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
+
   // Gets the tooltip text for labels that are wider than their bounds, except
   // when the label is multiline, in which case it just returns false (no
   // tooltip).  If a custom tooltip has been specified with SetTooltipText()
   // it is returned instead.
-  virtual bool GetTooltipText(const gfx::Point& p, std::wstring* tooltip);
-  virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
+  bool GetTooltipText(const gfx::Point& p, string16* tooltip);
 
  protected:
   // Called by Paint to paint the text.  Override this to change how
diff --git a/views/controls/label_unittest.cc b/views/controls/label_unittest.cc
index d0a162f..db3d491 100644
--- a/views/controls/label_unittest.cc
+++ b/views/controls/label_unittest.cc
@@ -110,19 +110,19 @@ TEST(LabelTest, MultiLineProperty) {
 
 TEST(LabelTest, TooltipProperty) {
   Label label;
-  std::wstring test_text(L"My cool string.");
-  label.SetText(test_text);
+  string16 test_text(ASCIIToUTF16("My cool string."));
+  label.SetText(UTF16ToWideHack(test_text));
 
-  std::wstring tooltip;
+  string16 tooltip;
   EXPECT_TRUE(label.GetTooltipText(gfx::Point(), &tooltip));
   EXPECT_EQ(test_text, tooltip);
 
-  std::wstring tooltip_text(L"The tooltip!");
+  string16 tooltip_text(ASCIIToUTF16("The tooltip!"));
   label.SetTooltipText(tooltip_text);
   EXPECT_TRUE(label.GetTooltipText(gfx::Point(), &tooltip));
   EXPECT_EQ(tooltip_text, tooltip);
 
-  std::wstring empty_text;
+  string16 empty_text;
   label.SetTooltipText(empty_text);
   EXPECT_TRUE(label.GetTooltipText(gfx::Point(), &tooltip));
   EXPECT_EQ(test_text, tooltip);
diff --git a/views/controls/menu/menu_delegate.cc b/views/controls/menu/menu_delegate.cc
index 9a3b177..eea9fd4 100644
--- a/views/controls/menu/menu_delegate.cc
+++ b/views/controls/menu/menu_delegate.cc
@@ -21,9 +21,8 @@ const gfx::Font& MenuDelegate::GetLabelFont(int id) const {
   return MenuConfig::instance().font;
 }
 
-std::wstring MenuDelegate::GetTooltipText(int id,
-                                          const gfx::Point& screen_loc) {
-  return std::wstring();
+string16 MenuDelegate::GetTooltipText(int id, const gfx::Point& screen_loc) {
+  return string16();
 }
 
 bool MenuDelegate::GetAccelerator(int id, Accelerator* accelerator) {
diff --git a/views/controls/menu/menu_delegate.h b/views/controls/menu/menu_delegate.h
index f76569e..9d7c8a2 100644
--- a/views/controls/menu/menu_delegate.h
+++ b/views/controls/menu/menu_delegate.h
@@ -66,7 +66,7 @@ class VIEWS_EXPORT MenuDelegate {
 
   // The tooltip shown for the menu item. This is invoked when the user
   // hovers over the item, and no tooltip text has been set for that item.
-  virtual std::wstring GetTooltipText(int id, const gfx::Point& screen_loc);
+  virtual string16 GetTooltipText(int id, const gfx::Point& screen_loc);
 
   // If there is an accelerator for the menu item with id |id| it is set in
   // |accelerator| and true is returned.
diff --git a/views/controls/menu/menu_item_view.cc b/views/controls/menu/menu_item_view.cc
index 86e6a70..ff9c0e3 100644
--- a/views/controls/menu/menu_item_view.cc
+++ b/views/controls/menu/menu_item_view.cc
@@ -40,7 +40,7 @@ class EmptyMenuMenuItem : public MenuItemView {
     SetEnabled(false);
   }
 
-  virtual bool GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE {
     // Empty menu items shouldn't have a tooltip.
     return false;
   }
@@ -101,8 +101,8 @@ void MenuItemView::ChildPreferredSizeChanged(View* child) {
   PreferredSizeChanged();
 }
 
-bool MenuItemView::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
-  *tooltip = UTF16ToWideHack(tooltip_);
+bool MenuItemView::GetTooltipText(const gfx::Point& p, string16* tooltip) {
+  *tooltip = tooltip_;
   if (!tooltip->empty())
     return true;
 
@@ -297,10 +297,10 @@ void MenuItemView::SetSelected(bool selected) {
   SchedulePaint();
 }
 
-void MenuItemView::SetTooltip(const std::wstring& tooltip, int item_id) {
+void MenuItemView::SetTooltip(const string16& tooltip, int item_id) {
   MenuItemView* item = GetMenuItemByID(item_id);
   DCHECK(item);
-  item->tooltip_ = WideToUTF16Hack(tooltip);
+  item->tooltip_ = tooltip;
 }
 
 void MenuItemView::SetIcon(const SkBitmap& icon, int item_id) {
diff --git a/views/controls/menu/menu_item_view.h b/views/controls/menu/menu_item_view.h
index 6b91c8d..beb487b 100644
--- a/views/controls/menu/menu_item_view.h
+++ b/views/controls/menu/menu_item_view.h
@@ -111,8 +111,7 @@ class VIEWS_EXPORT MenuItemView : public View {
   explicit MenuItemView(MenuDelegate* delegate);
 
   // Overridden from View:
-  virtual bool GetTooltipText(const gfx::Point& p,
-                              std::wstring* tooltip) OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
   // Returns the preferred height of menu items. This is only valid when the
@@ -243,7 +242,7 @@ class VIEWS_EXPORT MenuItemView : public View {
   bool IsSelected() const { return selected_; }
 
   // Sets the |tooltip| for a menu item view with |item_id| identifier.
-  void SetTooltip(const std::wstring& tooltip, int item_id);
+  void SetTooltip(const string16& tooltip, int item_id);
 
   // Sets the icon for the descendant identified by item_id.
   void SetIcon(const SkBitmap& icon, int item_id);
diff --git a/views/controls/progress_bar.cc b/views/controls/progress_bar.cc
index 7091500..f15f5dd 100644
--- a/views/controls/progress_bar.cc
+++ b/views/controls/progress_bar.cc
@@ -289,11 +289,11 @@ void ProgressBar::OnPaint(gfx::Canvas* canvas) {
 #endif
 }
 
-bool ProgressBar::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+bool ProgressBar::GetTooltipText(const gfx::Point& p, string16* tooltip) {
   DCHECK(tooltip);
   if (tooltip == NULL)
     return false;
-  tooltip->assign(UTF16ToWideHack(tooltip_text_));
+  tooltip->assign(tooltip_text_);
   return !tooltip_text_.empty();
 }
 
@@ -315,8 +315,8 @@ void ProgressBar::SetValue(double value) {
   }
 }
 
-void ProgressBar::SetTooltipText(const std::wstring& tooltip_text) {
-  tooltip_text_ = WideToUTF16Hack(tooltip_text);
+void ProgressBar::SetTooltipText(const string16& tooltip_text) {
+  tooltip_text_ = tooltip_text;
 }
 
 }  // namespace views
diff --git a/views/controls/progress_bar.h b/views/controls/progress_bar.h
index 5156c8f..c4d3f24 100644
--- a/views/controls/progress_bar.h
+++ b/views/controls/progress_bar.h
@@ -39,8 +39,7 @@ class VIEWS_EXPORT ProgressBar : public View {
   virtual std::string GetClassName() const OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
-  virtual bool GetTooltipText(const gfx::Point& p, std::wstring* tooltip)
-      OVERRIDE;
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
 
   // Sets the inclusive range of values to be displayed.  Values outside of the
   // range will be capped when displayed.
@@ -54,7 +53,7 @@ class VIEWS_EXPORT ProgressBar : public View {
   // Sets the tooltip text.  Default behavior for a progress bar is to show no
   // tooltip on mouse hover. Calling this lets you set a custom tooltip.  To
   // revert to default behavior, call this with an empty string.
-  virtual void SetTooltipText(const std::wstring& tooltip_text);
+  void SetTooltipText(const string16& tooltip_text);
 
 
  private:
diff --git a/views/controls/progress_bar_unittest.cc b/views/controls/progress_bar_unittest.cc
index 16f1581..7d62b99 100644
--- a/views/controls/progress_bar_unittest.cc
+++ b/views/controls/progress_bar_unittest.cc
@@ -12,10 +12,10 @@ namespace views {
 
 TEST(ProgressBarTest, TooltipTextProperty) {
   ProgressBar bar;
-  std::wstring tooltip = L"Some text";
+  string16 tooltip = ASCIIToUTF16("Some text");
   EXPECT_FALSE(bar.GetTooltipText(gfx::Point(), &tooltip));
-  EXPECT_EQ(L"", tooltip);
-  std::wstring tooltip_text = L"My progress";
+  EXPECT_EQ(string16(), tooltip);
+  string16 tooltip_text = ASCIIToUTF16("My progress");
   bar.SetTooltipText(tooltip_text);
   EXPECT_TRUE(bar.GetTooltipText(gfx::Point(), &tooltip));
   EXPECT_EQ(tooltip_text, tooltip);
diff --git a/views/controls/table/native_table_win.cc b/views/controls/table/native_table_win.cc
index 209959d..1a568cf 100644
--- a/views/controls/table/native_table_win.cc
+++ b/views/controls/table/native_table_win.cc
@@ -324,7 +324,7 @@ bool NativeTableWin::ProcessMessage(UINT message, WPARAM w_param,
         // be called when dwFlags would be LVGIT_UNFOLDED.  Removing it entirely
         // will disable all of the above behavior.
         NMLVGETINFOTIP* info_tip = reinterpret_cast<NMLVGETINFOTIP*>(hdr);
-        std::wstring tooltip = table_->model()->GetTooltip(info_tip->iItem);
+        string16 tooltip = table_->model()->GetTooltip(info_tip->iItem);
         CHECK(info_tip->cchTextMax >= 2);
         if (tooltip.length() >= static_cast<size_t>(info_tip->cchTextMax)) {
           // Elide the tooltip if necessary.
diff --git a/views/controls/table/table_view.cc b/views/controls/table/table_view.cc
index c761bb6..b6b6bb5 100644
--- a/views/controls/table/table_view.cc
+++ b/views/controls/table/table_view.cc
@@ -1080,13 +1080,13 @@ LRESULT TableView::OnNotify(int w_param, LPNMHDR hdr) {
       // called when dwFlags would be LVGIT_UNFOLDED.  Removing it entirely will
       // disable all of the above behavior.
       NMLVGETINFOTIP* info_tip = reinterpret_cast<NMLVGETINFOTIP*>(hdr);
-      std::wstring tooltip =
+      string16 tooltip =
           model_->GetTooltip(ViewToModel(info_tip->iItem));
       CHECK(info_tip->cchTextMax >= 2);
       if (tooltip.length() >= static_cast<size_t>(info_tip->cchTextMax)) {
         tooltip.erase(info_tip->cchTextMax - 2);  // Ellipsis + '\0'
-        const wchar_t kEllipsis = L'\x2026';
-        tooltip += kEllipsis;
+        const char16 kEllipsis = 0x2026;
+        tooltip.push_back(kEllipsis);
       }
       if (!tooltip.empty())
         wcscpy_s(info_tip->pszText, tooltip.length() + 1, tooltip.c_str());
diff --git a/views/view.cc b/views/view.cc
index 7ea42bf..dfd8f2f 100644
--- a/views/view.cc
+++ b/views/view.cc
@@ -944,7 +944,7 @@ FocusTraversable* View::GetPaneFocusTraversable() {
 
 // Tooltips --------------------------------------------------------------------
 
-bool View::GetTooltipText(const gfx::Point& p, std::wstring* tooltip) {
+bool View::GetTooltipText(const gfx::Point& p, string16* tooltip) {
   return false;
 }
 
diff --git a/views/view.h b/views/view.h
index 4cd9274..c12c2bd2 100644
--- a/views/view.h
+++ b/views/view.h
@@ -736,7 +736,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
   // Any time the tooltip text that a View is displaying changes, it must
   // invoke TooltipTextChanged.
   // |p| provides the coordinates of the mouse (relative to this view).
-  virtual bool GetTooltipText(const gfx::Point& p, std::wstring* tooltip);
+  virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip);
 
   // Returns the location (relative to this View) for the text on the tooltip
   // to display. If false is returned (the default), the tooltip is placed at
diff --git a/views/widget/tooltip_manager.cc b/views/widget/tooltip_manager.cc
index 1323318..db15c9e 100644
--- a/views/widget/tooltip_manager.cc
+++ b/views/widget/tooltip_manager.cc
@@ -13,17 +13,17 @@
 namespace {
 
 // Maximum number of characters we allow in a tooltip.
-static const size_t kMaxTooltipLength = 1024;
+const size_t kMaxTooltipLength = 1024;
 
 // Maximum number of lines we allow in the tooltip.
-static const size_t kMaxLines = 6;
+const size_t kMaxLines = 6;
 
 }  // anonymous namespace
 
 namespace views {
 
 // static
-void TooltipManager::TrimTooltipToFit(std::wstring* text,
+void TooltipManager::TrimTooltipToFit(string16* text,
                                       int* max_width,
                                       int* line_count,
                                       int x,
@@ -41,7 +41,7 @@ void TooltipManager::TrimTooltipToFit(std::wstring* text,
 
   // Split the string into at most kMaxLines lines.
   std::vector<string16> lines;
-  base::SplitString(WideToUTF16(*text), '\n', &lines);
+  base::SplitString(*text, '\n', &lines);
   if (lines.size() > kMaxLines)
     lines.resize(kMaxLines);
   *line_count = static_cast<int>(lines.size());
@@ -57,7 +57,7 @@ void TooltipManager::TrimTooltipToFit(std::wstring* text,
       result.push_back('\n');
     result.append(elided_text);
   }
-  *text = UTF16ToWideHack(result);
+  *text = result;
 }
 
 }  // namespace views
diff --git a/views/widget/tooltip_manager.h b/views/widget/tooltip_manager.h
index e58f79c..6b4c8d9 100644
--- a/views/widget/tooltip_manager.h
+++ b/views/widget/tooltip_manager.h
@@ -9,6 +9,7 @@
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/string16.h"
 #include "views/views_export.h"
 
 namespace gfx {
@@ -55,7 +56,7 @@ class VIEWS_EXPORT TooltipManager {
   // |max_width| to the width (in pixels) of the clipped text and |line_count|
   // to the number of lines of text in the tooltip. |x| and |y| give the
   // location of the tooltip in screen coordinates.
-  static void TrimTooltipToFit(std::wstring* text,
+  static void TrimTooltipToFit(string16* text,
                                int* max_width,
                                int* line_count,
                                int x,
diff --git a/views/widget/tooltip_manager_gtk.cc b/views/widget/tooltip_manager_gtk.cc
index eb5bf20..8515fa9 100644
--- a/views/widget/tooltip_manager_gtk.cc
+++ b/views/widget/tooltip_manager_gtk.cc
@@ -93,7 +93,7 @@ bool TooltipManagerGtk::ShowTooltip(int x, int y, bool for_keyboard,
   if (!view)
     return false;
 
-  std::wstring text;
+  string16 text;
   if (!view->GetTooltipText(view_loc, &text))
     return false;
 
@@ -138,7 +138,7 @@ void TooltipManagerGtk::ShowKeyboardTooltip(View* view) {
   // We have to hide the current tooltip, then show again.
   HideKeyboardTooltip();
 
-  std::wstring tooltip_text;
+  string16 tooltip_text;
   if (!view->GetTooltipText(gfx::Point(), &tooltip_text))
     return;  // The view doesn't have a tooltip, nothing to do.
 
diff --git a/views/widget/tooltip_manager_views.cc b/views/widget/tooltip_manager_views.cc
index 15964d7..7156b57 100644
--- a/views/widget/tooltip_manager_views.cc
+++ b/views/widget/tooltip_manager_views.cc
@@ -158,7 +158,7 @@ View* TooltipManagerViews::GetViewForTooltip(int x, int y, bool for_keyboard) {
 
 void TooltipManagerViews::UpdateIfRequired(int x, int y, bool for_keyboard) {
   View* view = GetViewForTooltip(x, y, for_keyboard);
-  std::wstring tooltip_text;
+  string16 tooltip_text;
   if (view)
     view->GetTooltipText(gfx::Point(x, y), &tooltip_text);
 
@@ -177,7 +177,7 @@ void TooltipManagerViews::Update() {
     tooltip_widget_->Hide();
   } else {
     int max_width, line_count;
-    std::wstring tooltip_text(tooltip_text_);
+    string16 tooltip_text(tooltip_text_);
     TrimTooltipToFit(&tooltip_text, &max_width, &line_count,
                      curr_mouse_pos_.x(), curr_mouse_pos_.y());
     tooltip_label_.SetText(tooltip_text);
diff --git a/views/widget/tooltip_manager_views.h b/views/widget/tooltip_manager_views.h
index 3a154df..ced0ea2 100644
--- a/views/widget/tooltip_manager_views.h
+++ b/views/widget/tooltip_manager_views.h
@@ -80,7 +80,7 @@ class TooltipManagerViews : public TooltipManager,
   scoped_ptr<Widget> tooltip_widget_;
   internal::RootView* root_view_;
   View* tooltip_view_;
-  std::wstring tooltip_text_;
+  string16 tooltip_text_;
   Label tooltip_label_;
 
   gfx::Point curr_mouse_pos_;
diff --git a/views/widget/tooltip_manager_win.cc b/views/widget/tooltip_manager_win.cc
index 061518c..b35e381 100644
--- a/views/widget/tooltip_manager_win.cc
+++ b/views/widget/tooltip_manager_win.cc
@@ -278,7 +278,7 @@ void TooltipManagerWin::UpdateTooltip(const gfx::Point& mouse_pos) {
     // text has changed.
     gfx::Point view_point = mouse_pos;
     View::ConvertPointToView(root_view, last_tooltip_view_, &view_point);
-    std::wstring new_tooltip_text;
+    string16 new_tooltip_text;
     bool has_tooltip_text =
         last_tooltip_view_->GetTooltipText(view_point, &new_tooltip_text);
     if (!has_tooltip_text || (new_tooltip_text != tooltip_text_)) {
@@ -322,7 +322,7 @@ void TooltipManagerWin::ShowKeyboardTooltip(View* focused_view) {
     tooltip_text_.clear();
   }
   HideKeyboardTooltip();
-  std::wstring tooltip_text;
+  string16 tooltip_text;
   if (!focused_view->GetTooltipText(gfx::Point(), &tooltip_text))
     return;
   gfx::Rect focused_bounds = focused_view->bounds();