MacViews: Enable views based External Protocol dialog behind secondary-ui-md flag.

chrome/browser/ui/browser_dialogs.h

Index: chrome/browser/ui/browser_dialogs.h
diff --git a/chrome/browser/ui/browser_dialogs.h b/chrome/browser/ui/browser_dialogs.h
index 6d2df0169030a256d3899b473bd0899e5bc1b1ff..14118fcfb8ce8a941218f9389881b540ee36f91e 100644
--- a/chrome/browser/ui/browser_dialogs.h
+++ b/chrome/browser/ui/browser_dialogs.h
@@ -13,6 +13,7 @@
 #include "build/build_config.h"
 #include "chrome/browser/ui/bookmarks/bookmark_editor.h"
 #include "third_party/skia/include/core/SkColor.h"
+#include "ui/base/page_transition_types.h"
 #include "ui/gfx/native_widget_types.h"
 
 #if defined(OS_CHROMEOS)
@@ -150,6 +151,13 @@ void ShowBookmarkEditorViews(gfx::NativeWindow parent_window,
                              const BookmarkEditor::EditDetails& details,
                              BookmarkEditor::Configuration configuration);
 
+// Shows the toolkit-views based External Protocol dialog.
+void RunExternalProtocolDialogViews(const GURL& url,

[tapted, 2017/01/17 21:17:13]

Does this need to be here, or can it be a data member of ExternalProtocolHandler
as well?

(maybe BUILDFLAG(MAC_VIEWS_BROWSER) will help do this now)

[karandeepb, 2017/01/19 03:59:43]

It can be a static member function. Don't think it should be public though,
since it's an implementation detail. Maybe a private static function. Although
this is similar to how we do this for other dialogs.

[tapted, 2017/01/20 05:53:52]

ExternalProtocolDialog currently uses static class functions - we should stick
with that

+                                    int render_process_host_id,
+                                    int routing_id,
+                                    ui::PageTransition page_transition,
+                                    bool has_user_gesture);
+
 void ShowPaymentRequestDialog(payments::PaymentRequest* request);
 
 #if defined(OS_MACOSX)