Add support for a "split" incognito behavior for extensions.

chrome/browser/extensions/extension_cookies_helpers.cc

Index: chrome/browser/extensions/extension_cookies_helpers.cc
diff --git a/chrome/browser/extensions/extension_cookies_helpers.cc b/chrome/browser/extensions/extension_cookies_helpers.cc
index 2aedb5f800da82049e10666c4043660aa00cfcde..52368e964b736085bd20e5edf53d5256c72a9218 100644
--- a/chrome/browser/extensions/extension_cookies_helpers.cc
+++ b/chrome/browser/extensions/extension_cookies_helpers.cc
@@ -27,9 +27,11 @@ Profile* ChooseProfileFromStoreId(const std::string& store_id,
                                   Profile* profile,
                                   bool include_incognito) {
   DCHECK(profile);
-  if (store_id == kOriginalProfileStoreId)
+  bool allow_original = !profile->IsOffTheRecord();
+  bool allow_incognito = profile->IsOffTheRecord() || include_incognito;
+  if (store_id == kOriginalProfileStoreId && allow_original)
     return profile->GetOriginalProfile();
-  if (store_id == kOffTheRecordProfileStoreId && include_incognito)
+  if (store_id == kOffTheRecordProfileStoreId && allow_incognito)
     return profile->GetOffTheRecordProfile();
   return NULL;
 }