Add initial support for runtime permissions in android M.

components/infobars/core/infobar_delegate.cc

Index: components/infobars/core/infobar_delegate.cc
diff --git a/components/infobars/core/infobar_delegate.cc b/components/infobars/core/infobar_delegate.cc
index 37fbdf79b09f6aeabf3cfedfcfd4b5af2a5aec33..d9f765518e38c6339d4910a4f5ca164b9d9c4bf3 100644
--- a/components/infobars/core/infobar_delegate.cc
+++ b/components/infobars/core/infobar_delegate.cc
@@ -68,6 +68,10 @@ NativeAppInfoBarDelegate* InfoBarDelegate::AsNativeAppInfoBarDelegate() {
   return nullptr;
 }
 
+PermissionInfobarDelegate* InfoBarDelegate::AsPermissionInfobarDelegate() {
+  return nullptr;
+}
+
 PopupBlockedInfoBarDelegate* InfoBarDelegate::AsPopupBlockedInfoBarDelegate() {
   return nullptr;
 }