Tests capturing MHTML snapshots.
Capturing without specified format:
From: <Saved by Blink>
<Snapshot-Content-Location: >Subject:
<Date: ><MIME-Version: >Content-Type: multipart/related;
type="text/html";
<boundary="----MultipartBoundary-->
<------MultipartBoundary-->Content-Type: text/html
<Content-ID: ><Content-Transfer-Encoding: ><Content-Location: >
<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html; charset=
=3Dwindows-1252"></head><body><div id=3D"x" class=3D"container">
<p style=3D"color: red">Text</p>
=20
</div>
</body></html>
<------MultipartBoundary-->
Capturing with format: foo
{
error : {
code : -32000
message : Unsupported snapshot format
}
id : <number>
sessionId : <string>
}