'View source code' option should be disabled in context menu for 'Paper Toolbar' of 'Pdf Viewer"

chrome/browser/renderer_context_menu/render_view_context_menu.cc

 // 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/renderer_context_menu/render_view_context_menu.h"
 
 #include <algorithm>
 #include <set>
 #include <utility>
 
@@ skipping 1135 matching lines @@
       if (!core_tab_helper)
         return false;
 
       CoreTabHelperDelegate* core_delegate = core_tab_helper->delegate();
       return !core_delegate ||
              core_delegate->CanReloadContents(embedder_web_contents_);
     }
 
     case IDC_VIEW_SOURCE:
     case IDC_CONTENT_CONTEXT_VIEWFRAMESOURCE:
+      if (!!extensions::MimeHandlerViewGuest::FromWebContents(
+              source_web_contents_)) {
+        return false;
+      }
       return (params_.media_type != WebContextMenuData::MediaTypePlugin) &&
              embedder_web_contents_->GetController().CanViewSource();
 
     case IDC_CONTENT_CONTEXT_INSPECTELEMENT:
     case IDC_CONTENT_CONTEXT_INSPECTBACKGROUNDPAGE:
     case IDC_CONTENT_CONTEXT_RELOAD_PACKAGED_APP:
     case IDC_CONTENT_CONTEXT_RESTART_PACKAGED_APP:
       return IsDevCommandEnabled(id);
 
     case IDC_CONTENT_CONTEXT_VIEWPAGEINFO:
@@ skipping 811 matching lines @@
   source_web_contents_->GetRenderViewHost()->
       ExecuteMediaPlayerActionAtLocation(location, action);
 }
 
 void RenderViewContextMenu::PluginActionAt(
     const gfx::Point& location,
     const WebPluginAction& action) {
   source_web_contents_->GetRenderViewHost()->
       ExecutePluginActionAtLocation(location, action);
 }