Allow URL requests for object/embed tags to be intercepted as streams.

content/browser/loader/buffered_resource_handler.cc

Index: content/browser/loader/buffered_resource_handler.cc
diff --git a/content/browser/loader/buffered_resource_handler.cc b/content/browser/loader/buffered_resource_handler.cc
index f96b5506d8c455f1526a89b3917d5e65bb3d82dd..f308b470529cf48586d02ecc52368d7ba21a46ae 100644
--- a/content/browser/loader/buffered_resource_handler.cc
+++ b/content/browser/loader/buffered_resource_handler.cc
@@ -312,6 +312,15 @@ bool BufferedResourceHandler::SelectNextHandler(bool* defer) {
     return UseAlternateNextHandler(handler.Pass(), std::string());
   }
 
+  // Allow requests for object/embed tags to be intercepted as streams.
+  if (info->GetResourceType() == content::RESOURCE_TYPE_OBJECT) {

[Zachary Kuznia, 2014/11/13 23:18:08]

Why isn't this caught by line 333?

[raymes, 2014/11/13 23:42:10]

Because in these cases |allow_download| is always false. The reason is that
allow_download is only ever true if the resource types are frames (see
https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/lo...).

This makes sense because if the request isn't coming from a frame we don't want
the browser to download it.

[Zachary Kuznia, 2014/11/13 23:48:42]

It feels like we should share this call with the other case, instead of copying
it.  However, that might made the code harder to read...  Can you think of a way
to re-arrange this so that MaybeInterceptAsStream has only one call site in this
function?

[raymes, 2014/11/14 20:55:29]

I did try to share the code in a few different ways but none of them seemed to
make it clearer. If we have a function, it needs to have a return value which is
a bool indicating whether the stream was intercepted and an out param which is a
bool which indicates the return value which felt a bit awkward. If you prefer
this, let me know and I can make the change :)

[Zachary Kuznia, 2014/11/14 22:01:45]

Fair enough, I thought that might be the case.

+    DCHECK(!info->allow_download());
+    std::string payload;
+    scoped_ptr<ResourceHandler> handler(
+        host_->MaybeInterceptAsStream(request(), response_.get(), &payload));
+    return UseAlternateNextHandler(handler.Pass(), payload);

[Zachary Kuznia, 2014/11/13 23:18:08]

Is there a reason not to test that handler is set?

[raymes, 2014/11/13 23:42:10]

There is one other place where requests are made on behalf of objects which is
for pnacl pexes:
https://code.google.com/p/chromium/codesearch#chromium/src/components/nacl/re...

In those cases the request might not be intercepted as a stream.

[Zachary Kuznia, 2014/11/13 23:48:42]

In that case, shouldn't we maintain the current behavior of returning true, like
like 325?

[raymes, 2014/11/14 20:55:29]

Yes, good catch! I added a test for this.

+  }
+
   if (!info->allow_download())
     return true;