Replace the WAS_INSTALLED_BY_CUSTODIAN creation flag with a pref

chrome/browser/extensions/extension_util.h

Index: chrome/browser/extensions/extension_util.h
diff --git a/chrome/browser/extensions/extension_util.h b/chrome/browser/extensions/extension_util.h
index 7fa21e4bbe8f8ba2d766a707e1eeaa7d44109a8e..22863b2ebfd5f2816c71a1a18a553dacbb224ebc 100644
--- a/chrome/browser/extensions/extension_util.h
+++ b/chrome/browser/extensions/extension_util.h
@@ -63,6 +63,13 @@ void SetAllowFileAccess(const std::string& extension_id,
                         content::BrowserContext* context,
                         bool allow);
 
+// Sets whether |extension_id| is installed by a custodian.
+// This is relevant for supervised users and is used to limit their privileges
+// for extensions installed by their custodian (e.g. they cannot uninstall them)
+void SetWasInstalledByCustodian(const std::string& extension_id,
+                                content::BrowserContext* context,
+                                bool installed_by_custodian);
+
 // Returns true if the extension with |extension_id| is allowed to execute
 // scripts on all urls (exempting chrome:// urls, etc) without explicit
 // user consent.