Add delegate to install web_contents helpers for MimeHandlerView.

chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc

Index: chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc
diff --git a/chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc b/chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..10318ecca0d8b9b523c215db50215a1397ebbd3f
--- /dev/null
+++ b/chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.cc
@@ -0,0 +1,39 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_guest_delegate.h"
+
+#include "chrome/browser/ui/pdf/chrome_pdf_web_contents_helper_client.h"
+#include "components/pdf/browser/pdf_web_contents_helper.h"
+
+#if defined(ENABLE_PRINTING)
+#if defined(ENABLE_FULL_PRINTING)
+#include "chrome/browser/printing/print_preview_message_handler.h"
+#include "chrome/browser/printing/print_view_manager.h"
+#else
+#include "chrome/browser/printing/print_view_manager_basic.h"
+#endif  // defined(ENABLE_FULL_PRINTING)
+#endif  // defined(ENABLE_PRINTING)
+
+ChromeMimeHandlerViewGuestDelegate::ChromeMimeHandlerViewGuestDelegate() {
+}
+
+ChromeMimeHandlerViewGuestDelegate::~ChromeMimeHandlerViewGuestDelegate() {
+}
+
+void ChromeMimeHandlerViewGuestDelegate::OnAttachHelpers(
+    content::WebContents* web_contents) {
+#if defined(ENABLE_PRINTING)

[Fady Samuel, 2014/09/09 02:10:24]

TODO to move this stuff to extensions perhaps?

[lazyboy, 2014/09/09 06:57:42]

Done.

+#if defined(ENABLE_FULL_PRINTING)
+  printing::PrintViewManager::CreateForWebContents(web_contents);
+  printing::PrintPreviewMessageHandler::CreateForWebContents(web_contents);
+#else
+  printing::PrintViewManagerBasic::CreateForWebContents(web_contents);
+#endif  // defined(ENABLE_FULL_PRINTING)
+#endif  // defined(ENABLE_PRINTING)
+  pdf::PDFWebContentsHelper::CreateForWebContentsWithClient(
+      web_contents,
+      scoped_ptr<pdf::PDFWebContentsHelperClient>(
+          new ChromePDFWebContentsHelperClient()));
+}