Remove popup overlay from MHTML when requested

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index ce8f2725ee2b813aa94e0886dfe200be4c48e5da..11cc600ec101c35e25e013c7612654ef8dba0077 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -782,6 +782,10 @@ class MHTMLPartsGenerationDelegate
 
   bool useBinaryEncoding() override { return params_.mhtml_binary_encoding; }
 
+  bool removePopupOverlay() override {
+    return params_.mhtml_popup_overlay_removal;
+  }
+
  private:
   const FrameMsg_SerializeAsMHTML_Params& params_;
   std::set<std::string>* serialized_resources_uri_digests_;