Add method for identifying different InfoBars

chrome/browser/ui/cocoa/keystone_infobar_delegate.mm

Index: chrome/browser/ui/cocoa/keystone_infobar_delegate.mm
diff --git a/chrome/browser/ui/cocoa/keystone_infobar_delegate.mm b/chrome/browser/ui/cocoa/keystone_infobar_delegate.mm
index 012767892664850987510207573a282e32c4b71e..9553479b7b58383a41a473fd137f5923ab1b3b32 100644
--- a/chrome/browser/ui/cocoa/keystone_infobar_delegate.mm
+++ b/chrome/browser/ui/cocoa/keystone_infobar_delegate.mm
@@ -52,6 +52,7 @@ class KeystonePromotionInfoBarDelegate : public ConfirmInfoBarDelegate {
   void SetCanExpire() { can_expire_ = true; }
 
   // ConfirmInfoBarDelegate
+  infobars::InfoBarDelegate::InfoBarIdentifier GetIdentifier() const override;
   int GetIconId() const override;
   bool ShouldExpire(const NavigationDetails& details) const override;
   base::string16 GetMessageText() const override;
@@ -105,6 +106,11 @@ KeystonePromotionInfoBarDelegate::KeystonePromotionInfoBarDelegate(
 KeystonePromotionInfoBarDelegate::~KeystonePromotionInfoBarDelegate() {
 }
 
+infobars::InfoBarDelegate::InfoBarIdentifier
+KeystonePromotionInfoBarDelegate::GetIdentifier() const {
+  return KEYSTONE_PROMOTION_INFOBAR_DELEGATE_ID;
+}
+
 int KeystonePromotionInfoBarDelegate::GetIconId() const {
   return IDR_PRODUCT_LOGO_32;
 }