REGRESSION (173394): Support for webcam is broken
https://bugs.webkit.org/show_bug.cgi?id=139313

Reviewed by Alexey Proskuryakov.

Source/WebKit2:

* NetworkProcess/NetworkResourceLoader.cpp:
(WebKit::NetworkResourceLoader::didReceiveResponseAsync):

    Don't buffer when handling multipart/x-mixed-replace. Multiple calls to didReceiveResponseAsync break assumptions.

LayoutTests:

We had no coverage for actually rendering multipart content.

* http/tests/multipart/multipart-image-expected.html: Added.
* http/tests/multipart/multipart-image.html: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@176905 268f45cc-cd09-0410-ab3c-d52691b4dbfc