clean up message "External extension with id xxxx has been uninstalled by ..."

extensions/browser/extension_prefs.cc

Index: extensions/browser/extension_prefs.cc
diff --git a/extensions/browser/extension_prefs.cc b/extensions/browser/extension_prefs.cc
index 56645a72564cfaf2ff64c922cec00eb1f5edd514..d109ecd076736dbfead29cb9c291c9dbf68dc9f2 100644
--- a/extensions/browser/extension_prefs.cc
+++ b/extensions/browser/extension_prefs.cc
@@ -1259,8 +1259,8 @@ std::unique_ptr<ExtensionInfo> ExtensionPrefs::GetInstalledExtensionInfo(
   int state_value;
   if (ext->GetInteger(kPrefState, &state_value) &&
       state_value == Extension::EXTERNAL_EXTENSION_UNINSTALLED) {
-    LOG(WARNING) << "External extension with id " << extension_id
-                 << " has been uninstalled by the user";
+    DLOG(WARNING) << "External extension with id " << extension_id
+                  << " has been uninstalled by the user";

[asargent_no_longer_on_chrome, 2016/10/05 18:05:01]

I think it's safe to just remove this; as far as I know it has either rarely or
never been helpful in tracking down actual problems. 

     return std::unique_ptr<ExtensionInfo>();
   }