Fix the extension activity log UI.

chrome/browser/ui/webui/extensions/extensions_ui.cc

Index: chrome/browser/ui/webui/extensions/extensions_ui.cc
diff --git a/chrome/browser/ui/webui/extensions/extensions_ui.cc b/chrome/browser/ui/webui/extensions/extensions_ui.cc
index d6852429f9c782b9ad88875c7b43873b8c866ffe..62b61844b76de473735e1c1d82ce6e3f3c04ff3d 100644
--- a/chrome/browser/ui/webui/extensions/extensions_ui.cc
+++ b/chrome/browser/ui/webui/extensions/extensions_ui.cc
@@ -11,6 +11,7 @@
 #include "chrome/browser/ui/webui/extensions/extension_settings_handler.h"
 #include "chrome/browser/ui/webui/extensions/install_extension_handler.h"
 #include "chrome/browser/ui/webui/extensions/pack_extension_handler.h"
+#include "chrome/browser/ui/webui/generic_handler.h"
 #include "chrome/browser/ui/webui/shared_resources_data_source.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/web_ui.h"
@@ -57,6 +58,8 @@ ExtensionsUI::ExtensionsUI(content::WebUI* web_ui) : WebUIController(web_ui) {
       new InstallExtensionHandler();
   install_extension_handler->GetLocalizedValues(source->localized_strings());
   web_ui->AddMessageHandler(install_extension_handler);
+
+  web_ui->AddMessageHandler(new GenericHandler());
 }
 
 ExtensionsUI::~ExtensionsUI() {