Making PageSerializer operate on single frames only.

third_party/WebKit/Source/web/WebPageSerializer.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 66 matching lines @@
 bool MHTMLPageSerializerDelegate::shouldIgnoreAttribute(const Attribute& attribute)
 {
     // TODO(fgorski): Presence of srcset attribute causes MHTML to not display images, as only the value of src
     // is pulled into the archive. Discarding srcset prevents the problem. Long term we should make sure to MHTML
     // plays nicely with srcset.
     return attribute.localName() == HTMLNames::srcsetAttr;
 }
 
 } // namespace
 
 static PassRefPtr<SharedBuffer> serializePageToMHTML(Page* page, MHTMLArchive::EncodingPolicy encodingPolicy)

[dcheng, 2015/11/12 23:47:32]

Is this covered by any tests right now?

[Łukasz Anforowicz, 2015/11/13 00:22:10]

If "this" = "serializePageToMHTML function", then it is exercised by
WebContents::GenerateMHTML and is covered by tests in
chrome/browser/downloads/save_page_browsertest.cc and in
content/browser/download/mhtml_generation_browsertest.cc.  I've recently
increased the coverage in crrev.com/1412733017 and will further improve coverage
in crrev.com/1442733002.

If "this" = "encodingPolicy parameter" , then *binary* encoding of MHTML is not
covered by tests AFAIK.  YOTOH, WebContents::GenerateMHTML is hardcoded to use
the default, non-binary encoding.  AFAIK the binary encoding is only exposed via
Blink public API.  I guess I should do some git history research to see if it
can be yanked out altogether.

 {
     Vector<SerializedResource> resources;
+    HashSet<KURL> alreadySerializedUrls;
     PageSerializer serializer(&resources, adoptPtr(new MHTMLPageSerializerDelegate));
-    serializer.serialize(page);
+
+    RefPtr<SharedBuffer> output = SharedBuffer::create();
+    String boundary = MHTMLArchive::generateMHTMLBoundary();
+
     Document* document = page->deprecatedLocalMainFrame()->document();
-    return MHTMLArchive::generateMHTMLData(resources, encodingPolicy, document->title(), document->suggestedMIMEType());
+    MHTMLArchive::generateMHTMLHeader(
+        boundary, document->title(), document->suggestedMIMEType(), *output);
+
+    Frame* frame = page->deprecatedLocalMainFrame();
+    for (; frame; frame = frame->tree().traverseNext()) {
+        // TODO(lukasza): This causes incomplete MHTML for OOPIFs.
+        // (crbug.com/538766)
+        if (!frame->isLocalFrame())
+            continue;
+
+        resources.clear();
+        serializer.serializeFrame(toLocalFrame(frame));
+
+        for (const auto& resource : resources) {
+            if (alreadySerializedUrls.contains(resource.url))
+                continue;
+            alreadySerializedUrls.add(resource.url);
+
+            MHTMLArchive::generateMHTMLPart(
+                boundary, encodingPolicy, resource, *output);
+        }
+    }
+
+    MHTMLArchive::generateMHTMLFooter(boundary, *output);
+    return output.release();
 }
 
 WebCString WebPageSerializer::serializeToMHTML(WebView* view)
 {
     RefPtr<SharedBuffer> mhtml = serializePageToMHTML(toWebViewImpl(view)->page(), MHTMLArchive::UseDefaultEncoding);
     // FIXME: we are copying all the data here. Idealy we would have a WebSharedData().
     return WebCString(mhtml->data(), mhtml->size());
 }
 
 WebCString WebPageSerializer::serializeToMHTMLUsingBinaryEncoding(WebView* view)
@@ skipping 33 matching lines @@
 WebString WebPageSerializer::generateBaseTagDeclaration(const WebString& baseTarget)
 {
     // TODO(yosin) We should call |PageSerializer::baseTagDeclarationOf()|.
     if (baseTarget.isEmpty())
         return String("<base href=\".\">");
     String baseString = "<base href=\".\" target=\"" + static_cast<const String&>(baseTarget) + "\">";
     return baseString;
 }
 
 } // namespace blink