Get signals working in the EXTRA_DATA section of MHTML

content/browser/download/mhtml_generation_browsertest.cc

Index: content/browser/download/mhtml_generation_browsertest.cc
diff --git a/content/browser/download/mhtml_generation_browsertest.cc b/content/browser/download/mhtml_generation_browsertest.cc
index 6adf1212067e82662735802eb6ae34847e5b2cad..af1f00b28e53a4dd4f23672f2e540730a17b189b 100644
--- a/content/browser/download/mhtml_generation_browsertest.cc
+++ b/content/browser/download/mhtml_generation_browsertest.cc
@@ -15,6 +15,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/histogram_tester.h"
 #include "base/threading/thread_restrictions.h"
+#include "content/browser/download/mhtml_extra_data.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/common/frame_messages.h"
 #include "content/public/browser/render_process_host.h"
@@ -672,4 +673,35 @@ IN_PROC_BROWSER_TEST_F(MHTMLGenerationTest, RemovePopupOverlay) {
   EXPECT_THAT(mhtml, Not(HasSubstr("class=3D\"modal")));
 }
 
+IN_PROC_BROWSER_TEST_F(MHTMLGenerationTest, 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);
+
+  // Place the extra data we need into the web contents user data.
+  std::string signal_string(kFakeSignalData);
+  shell()->web_contents()->SetUserData(
+      content::kMHTMLExtraDataKey,
+      std::unique_ptr<base::SupportsUserData::Data>(
+          new content::MHTMLExtraData(std::string(signal_string))));
+
+  // Make the user data available on other threads by promising we are done
+  // here. shell()->web_contents()->DetachFromSequence();
+
+  GenerateMHTML(params, url);
+
+  EXPECT_TRUE(has_mhtml_callback_run());
+
+  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