Add more management policy checking after extension installed

extensions/common/extension.h

Index: extensions/common/extension.h
diff --git a/extensions/common/extension.h b/extensions/common/extension.h
index 4c76478b50de4fb8371c0ba542fa7e5953ef3e3a..391c7e521a658f4dd27589fb057afa3ee00380ca 100644
--- a/extensions/common/extension.h
+++ b/extensions/common/extension.h
@@ -102,7 +102,9 @@ class Extension : public base::RefCountedThreadSafe<Extension> {
     DISABLE_REMOTE_INSTALL = 1 << 11,
     DISABLE_INACTIVE_EPHEMERAL_APP = 1 << 12,  // Cached ephemeral apps are
                                                // disabled to prevent activity.
-    DISABLE_REASON_LAST = 1 << 13,  // This should always be the last value
+    DISABLE_EXTERNAL_EXTENSION = 1 << 13,  // External extensions might be
+                                           // disabled for user prompting.
+    DISABLE_REASON_LAST = 1 << 14,  // This should always be the last value
   };
 
   // A base class for parsed manifest data that APIs want to store on