Add "regular_only" scope to allowed scopes for ChromeSetting.clear().

chrome/common/extensions/api/types.json

Index: chrome/common/extensions/api/types.json
diff --git a/chrome/common/extensions/api/types.json b/chrome/common/extensions/api/types.json
index 0bbb66e5cd4c9a96291345cd257c5d5da7741fa2..0463ebdd382c9f111efef8dd0310876c80672623 100644
--- a/chrome/common/extensions/api/types.json
+++ b/chrome/common/extensions/api/types.json
@@ -101,7 +101,7 @@
                 "properties": {
                   "scope": {
                     "type": "string",
-                    "enum": ["regular", "incognito_persistent", "incognito_session_only"],
+                    "enum": ["regular", "regular_only", "incognito_persistent", "incognito_session_only"],
                     "optional": true,
                     "description": "Where to clear the setting (default: regular). One of<br><var>regular</var>: setting for the regular profile (which is inherited by the incognito profile if not overridden elsewhere),<br><var>regular_only</var>: setting for the regular profile only (not inherited by the incognito profile),<br><var>incognito_persistent</var>: setting for the incognito profile that survives browser restarts (overrides regular preferences),<br><var>incognito_session_only</var>: setting for the incognito profile that can only be set during an incognito session and is deleted when the incognito session ends (overrides regular and incognito_persistent preferences)."
                   }