Add delegate to install web_contents helpers for MimeHandlerView.

chrome/browser/extensions/api/chrome_extensions_api_client.cc

Index: chrome/browser/extensions/api/chrome_extensions_api_client.cc
diff --git a/chrome/browser/extensions/api/chrome_extensions_api_client.cc b/chrome/browser/extensions/api/chrome_extensions_api_client.cc
index 08bf08ddfab3fabb39cc4e8aa75700872d6f41ad..0eeb96389d379be804d1320a3e4e495723a30c58 100644
--- a/chrome/browser/extensions/api/chrome_extensions_api_client.cc
+++ b/chrome/browser/extensions/api/chrome_extensions_api_client.cc
@@ -8,6 +8,7 @@
 #include "chrome/browser/extensions/api/storage/sync_value_store_cache.h"
 #include "chrome/browser/guest_view/app_view/chrome_app_view_guest_delegate.h"
 #include "chrome/browser/guest_view/extension_options/extension_options_guest.h"
+#include "chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.h"
 #include "chrome/browser/guest_view/web_view/chrome_web_view_guest_delegate.h"
 #include "chrome/browser/guest_view/web_view/chrome_web_view_permission_helper_delegate.h"
 #include "content/public/browser/browser_context.h"
@@ -47,6 +48,14 @@ AppViewGuestDelegate* ChromeExtensionsAPIClient::CreateAppViewGuestDelegate()
   return new ChromeAppViewGuestDelegate();
 }
 
+scoped_ptr<MimeHandlerViewGuestDelegate>
+ChromeExtensionsAPIClient::CreateMimeHandlerViewGuestDelegate(
+    MimeHandlerViewGuest* guest) const {
+  return scoped_ptr<ChromeMimeHandlerViewGuestDelegate>(
+             new ChromeMimeHandlerViewGuestDelegate(guest))
+      .PassAs<MimeHandlerViewGuestDelegate>();
+}
+
 WebViewGuestDelegate* ChromeExtensionsAPIClient::CreateWebViewGuestDelegate(
     WebViewGuest* web_view_guest) const {
   return new ChromeWebViewGuestDelegate(web_view_guest);