Chrome Labs: Use shared constant for separator

Bug: 1145666
Change-Id: I71fd476656df5704a785fcde1a12db691cee7e6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2725791
Reviewed-by: Elly Fong-Jones <[email protected]>
Commit-Queue: Elaine Chien <[email protected]>
Cr-Commit-Position: refs/heads/master@{#858636}
diff --git a/components/flags_ui/feature_entry.h b/components/flags_ui/feature_entry.h
index 11165f4..d3d45f0 100644
--- a/components/flags_ui/feature_entry.h
+++ b/components/flags_ui/feature_entry.h
@@ -16,6 +16,8 @@
 
 namespace flags_ui {
 
+extern const char kMultiSeparatorChar;
+
 // Generic experiment choice option names.
 extern const char kGenericExperimentChoiceDefault[];
 extern const char kGenericExperimentChoiceEnabled[];