Revert external protocol handler user gesture fix on M36

chrome/browser/ui/tab_helpers.cc

Index: chrome/browser/ui/tab_helpers.cc
diff --git a/chrome/browser/ui/tab_helpers.cc b/chrome/browser/ui/tab_helpers.cc
index 05924e3767b77f4e4895d89d4a3ee6383fd11f32..ca1d604b3b2929a24c6d3cdc9331ea1b3e2c177d 100644
--- a/chrome/browser/ui/tab_helpers.cc
+++ b/chrome/browser/ui/tab_helpers.cc
@@ -40,6 +40,7 @@
 #else
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api.h"
 #include "chrome/browser/extensions/chrome_extension_web_contents_observer.h"
+#include "chrome/browser/external_protocol/external_protocol_observer.h"
 #include "chrome/browser/net/predictor_tab_helper.h"
 #include "chrome/browser/network_time/navigation_time_helper.h"
 #include "chrome/browser/plugins/plugin_observer.h"
@@ -153,6 +154,7 @@ void TabHelpers::AttachTabHelpers(WebContents* web_contents) {
   extensions::ChromeExtensionWebContentsObserver::CreateForWebContents(
       web_contents);
   extensions::WebNavigationTabObserver::CreateForWebContents(web_contents);
+  ExternalProtocolObserver::CreateForWebContents(web_contents);
   HungPluginTabHelper::CreateForWebContents(web_contents);
   ManagePasswordsUIController::CreateForWebContents(web_contents);
   NavigationTimeHelper::CreateForWebContents(web_contents);