Get signals working in the EXTRA_DATA section of MHTML

content/browser/download/mhtml_generation_browsertest.cc

 // Copyright (c) 2012 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 <stdint.h>
 #include <memory>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
@@ skipping 654 matching lines @@
   {
     base::ThreadRestrictions::ScopedAllowIO allow_io_for_content_verification;
     ASSERT_TRUE(base::ReadFileToString(path, &mhtml));
   }
 
   // Make sure the overlay is removed.
   EXPECT_THAT(mhtml, Not(HasSubstr("class=3D\"overlay")));
   EXPECT_THAT(mhtml, Not(HasSubstr("class=3D\"modal")));
 }
 
+IN_PROC_BROWSER_TEST_F(MHTMLGenerationSitePerProcessTest,
+                       GenerateMHTMLWithExtraData) {
+  const char kFakeSignalData = "FakeSignalData";
+  base::FilePath path(temp_dir_.GetPath());
+  path = path.Append(FILE_PATH_LITERAL("test.mht"));
+
+  GURL url(embedded_test_server()->GetURL("/page_with_image.html"));
+
+  MHTMLGenerationParams params(path);
+  params.remove_popup_overlay = true;
+  params.extra_data = kFakeSignalData;
+
+  GenerateMHTML(params, url);
+  ASSERT_FALSE(HasFailure());
+
+  std::string mhtml;
+  {
+    base::ThreadRestrictions::ScopedAllowIO allow_io_for_content_verification;
+    ASSERT_TRUE(base::ReadFileToString(path, &mhtml));
+  }
+
+  // Make sure that extra data made it into the mhtml.
+  EXPECT_THAT(mhtml, HasSubstr(kFakeSignalData));
+}
+
+
 }  // namespace content