Disable setting incognito prefs for extensions for now.

chrome/common/extensions/api/extension_api.json

Index: chrome/common/extensions/api/extension_api.json
diff --git a/chrome/common/extensions/api/extension_api.json b/chrome/common/extensions/api/extension_api.json
index f69c49d71027ea4c856a5d2d114933e80f5d7a13..5b76600759bb3511ab164971037d49c26667af35 100644
--- a/chrome/common/extensions/api/extension_api.json
+++ b/chrome/common/extensions/api/extension_api.json
@@ -5382,10 +5382,11 @@
                     "description": "The value of the preference. <br>Note that every preference has a specific value type, which is described together with the preference. An extension should <em>not</em> set a preference value of a different type.",
                     "type": "any"
                   },
-                  "incognito": {
-                    "type": "boolean",
+                  "scope": {
+                    "type": "string",
+                    "enum": ["regular"],

[Bernhard Bauer, 2011/05/24 20:14:57]

What are going to be the future values? "incognito_temporary" and
"incognito_persistent"? I'm not sure I really like that (but OTOH I don't have a
better suggestion either).

[battre, 2011/05/24 20:16:50]

My current proposal is "incognito_persistent" and "incognito_session_only".

[Bernhard Bauer, 2011/05/24 20:26:30]

Fine with me. Matt, any objections?

                     "optional": true,
-                    "description": "Whether to modify the setting for the incognito session only (default false)."
+                    "description": "Where to set the preference (default: regular). 'regular' = preference for regular profile (which is inherited by the incognito profile if not overridden elsewhere)."
                   }
                 }
               },
@@ -5406,12 +5407,13 @@
               {
                 "name": "details",
                 "type": "object",
-                "description": "What setting to clear.",
+                "description": "What preference to clear.",
                 "properties": {
-                  "incognito": {
-                    "type": "boolean",
+                  "scope": {
+                    "type": "string",
+                    "enum": ["regular"],
                     "optional": true,
-                    "description": "Whether to clear the setting for the incognito session only (default false)."
+                    "description": "Where to clear the preference (default: regular). 'regular' = preference for regular profile (which is inherited by the incognito profile if not overridden elsewhere)."
                   }
                 }
               },