[Extensions] Update Error Console UI

chrome/browser/extensions/api/developer_private/developer_private_api.cc

Index: chrome/browser/extensions/api/developer_private/developer_private_api.cc
diff --git a/chrome/browser/extensions/api/developer_private/developer_private_api.cc b/chrome/browser/extensions/api/developer_private/developer_private_api.cc
index 0c1ab7e9ee94f8f7bfe5c6aaf6ccc148921f36d0..03b8ee5e3140a91a2e1518dcf09fa46b6a364b2e 100644
--- a/chrome/browser/extensions/api/developer_private/developer_private_api.cc
+++ b/chrome/browser/extensions/api/developer_private/developer_private_api.cc
@@ -246,13 +246,21 @@ void DeveloperPrivateEventRouter::OnErrorAdded(const ExtensionError* error) {
   // We don't want to handle errors thrown by extensions subscribed to these
   // events (currently only the Apps Developer Tool), because doing so risks
   // entering a loop.
-  if (extension_ids_.find(error->extension_id()) != extension_ids_.end())
+  if (extension_ids_.count(error->extension_id()))
     return;
 
   BroadcastItemStateChanged(developer::EVENT_TYPE_ERROR_ADDED,
                             error->extension_id());
 }
 
+void DeveloperPrivateEventRouter::OnErrorsRemoved(
+    const std::set<std::string>& removed_ids) {
+  for (const std::string& id : removed_ids) {
+    if (!extension_ids_.count(id))
+      BroadcastItemStateChanged(developer::EVENT_TYPE_ERRORS_REMOVED, id);
+  }
+}
+
 void DeveloperPrivateEventRouter::OnExtensionFrameRegistered(
     const std::string& extension_id,
     content::RenderFrameHost* render_frame_host) {