This patch makes sure that successful HTTP requests, which result
in an error code, are passed to the catch() or reject handler, rather
than the success handler.
This results in two different cases in the claim() handler, that of
an internally thrown exception (like a TypeError), and that of a
Response() instance. In most cases, developers should not write
code that throws exceptions - and even in those, the ES6 Promise
API silently swallows most uncaught throws.
Change-Id: I736bcaccf6324a3d66191692e5f2ce922a727dea
528bccbf81