Convert infobar APIs to UTF-16.

chrome/browser/extensions/theme_installed_infobar_delegate.h

Index: chrome/browser/extensions/theme_installed_infobar_delegate.h
diff --git a/chrome/browser/extensions/theme_installed_infobar_delegate.h b/chrome/browser/extensions/theme_installed_infobar_delegate.h
index 09139a1e5e54b362f8e14bd392691a0b793f5c8f..2c54fa58edd4ebde9fbfda333cdbff6464bd6ed3 100644
--- a/chrome/browser/extensions/theme_installed_infobar_delegate.h
+++ b/chrome/browser/extensions/theme_installed_infobar_delegate.h
@@ -23,11 +23,11 @@ class ThemeInstalledInfoBarDelegate : public ConfirmInfoBarDelegate,
                                 const std::string& previous_theme_id);
   virtual ~ThemeInstalledInfoBarDelegate();
   virtual void InfoBarClosed();
-  virtual std::wstring GetMessageText() const;
+  virtual string16 GetMessageText() const;
   virtual SkBitmap* GetIcon() const;
   virtual ThemeInstalledInfoBarDelegate* AsThemePreviewInfobarDelegate();
   virtual int GetButtons() const;
-  virtual std::wstring GetButtonLabel(
+  virtual string16 GetButtonLabel(
       ConfirmInfoBarDelegate::InfoBarButton button) const;
   virtual bool Cancel();