Add method for identifying different InfoBars

chrome/browser/ui/extensions/extension_install_ui_default.cc

Index: chrome/browser/ui/extensions/extension_install_ui_default.cc
diff --git a/chrome/browser/ui/extensions/extension_install_ui_default.cc b/chrome/browser/ui/extensions/extension_install_ui_default.cc
index 704ff3ce1157290763cfc5667d5289eb0acfb8f3..3d49eb161ed5da2e27057c79de3d04e0afe96302 100644
--- a/chrome/browser/ui/extensions/extension_install_ui_default.cc
+++ b/chrome/browser/ui/extensions/extension_install_ui_default.cc
@@ -86,6 +86,7 @@ class ErrorInfoBarDelegate : public ConfirmInfoBarDelegate {
   ~ErrorInfoBarDelegate() override;
 
   // ConfirmInfoBarDelegate:
+  infobars::InfoBarDelegate::InfoBarIdentifier GetIdentifier() const override;
   base::string16 GetMessageText() const override;
   int GetButtons() const override;
   base::string16 GetLinkText() const override;
@@ -111,6 +112,11 @@ ErrorInfoBarDelegate::ErrorInfoBarDelegate(
 ErrorInfoBarDelegate::~ErrorInfoBarDelegate() {
 }
 
+infobars::InfoBarDelegate::InfoBarIdentifier
+ErrorInfoBarDelegate::GetIdentifier() const {
+  return INSTALLATION_ERROR_INFOBAR_DELEGATE_ID;
+}
+
 base::string16 ErrorInfoBarDelegate::GetMessageText() const {
   return error_.message();
 }