Fix an issue that external protocol in subframes are not handled on Android

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 df974a92d01639e03ee7a7e17d3d48a851ac8d15..99f01d4f1234a8cf63d1a48043898b29d76f5753 100644
--- a/chrome/browser/ui/tab_helpers.cc
+++ b/chrome/browser/ui/tab_helpers.cc
@@ -8,6 +8,7 @@
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/content_settings/chrome_content_settings_client.h"
 #include "chrome/browser/content_settings/tab_specific_content_settings.h"
+#include "chrome/browser/external_protocol/external_protocol_observer.h"
 #include "chrome/browser/favicon/favicon_helper.h"
 #include "chrome/browser/history/history_tab_helper.h"
 #include "chrome/browser/infobars/infobar_service.h"
@@ -45,7 +46,6 @@
 #include "chrome/browser/ui/android/context_menu_helper.h"
 #include "chrome/browser/ui/android/window_android_helper.h"
 #else
-#include "chrome/browser/external_protocol/external_protocol_observer.h"
 #include "chrome/browser/plugins/plugin_observer.h"
 #include "chrome/browser/safe_browsing/safe_browsing_tab_observer.h"
 #include "chrome/browser/thumbnails/thumbnail_tab_helper.h"
@@ -168,7 +168,6 @@ void TabHelpers::AttachTabHelpers(WebContents* web_contents) {
   extensions::ChromeExtensionWebContentsObserver::CreateForWebContents(
       web_contents);
   extensions::WebNavigationTabObserver::CreateForWebContents(web_contents);
-  ExternalProtocolObserver::CreateForWebContents(web_contents);
   HungPluginTabHelper::CreateForWebContents(web_contents);
   pdf::PDFWebContentsHelper::CreateForWebContentsWithClient(
       web_contents,
@@ -184,6 +183,7 @@ void TabHelpers::AttachTabHelpers(WebContents* web_contents) {
   ThumbnailTabHelper::CreateForWebContents(web_contents);
   web_modal::WebContentsModalDialogManager::CreateForWebContents(web_contents);
 #endif
+  ExternalProtocolObserver::CreateForWebContents(web_contents);
 
 #if defined(OS_WIN)
   MetroPinTabHelper::CreateForWebContents(web_contents);