Get signals working in the EXTRA_DATA section of MHTML

content/public/common/mhtml_generation_params.cc

Index: content/public/common/mhtml_generation_params.cc
diff --git a/content/public/common/mhtml_generation_params.cc b/content/public/common/mhtml_generation_params.cc
index 8d48664fdae6832e5cc1641a5873c1ab872a741a..b8f76052b3ddc762b730e28f2043c83580ab2a40 100644
--- a/content/public/common/mhtml_generation_params.cc
+++ b/content/public/common/mhtml_generation_params.cc
@@ -27,4 +27,14 @@ MHTMLGenerationParams::MHTMLGenerationParams(const base::FilePath& file_path)
   }
 }
 
+MHTMLGenerationParams::~MHTMLGenerationParams() {}
+
+MHTMLGenerationParams::MHTMLGenerationParams(
+    const MHTMLGenerationParams& other) {
+  file_path = other.file_path;
+  use_binary_encoding = other.use_binary_encoding;
+  cache_control_policy = other.cache_control_policy;
+  extra_data = other.extra_data;
+}
+
 }  // namespace content