Revert of Change ProxyResolver::GetProxyForURL() to take a scoped_ptr<Request>* rather than a RequestHandle* (patchset #11 id:200001 of https://codereview.chromium.org/1439053002/ )

Reason for revert:
Top crasher on Canary has PAC script cancellation on callstack. Very likely a bug or interaction with this CL.

Reverting until I have a chance to fully investigate.

Original issue's description:
> Change ProxyResolver::GetProxyForURL() to take a scoped_ptr<Request>* rather than a RequestHandle*
>
> * ProxyResolver::GetProxyForURL() fills a |scoped_pointer<Request>*|
>   rather than a |void*|
> * ProxyResolver::CancelRequest(void*) has been removed. Requests
>   are instead cancelled by resetting the scoped_ptr<Request>.
>
> This makes for less error prone code as cancellation of
> requests is automatic when the
> scoped_ptr<Request> goes out of scope.
> ProxyResolver::GetLoadState() is removed and replaced
> by Request::GetLoadState().
>
> Also made some renaming, as there were similar class
> named Job or Request. Now they are all Job and this new thing
> is Request.
>
> Referencing by address to object in vector was not wise in net/proxy/mojo_proxy_resolver_impl_unittest.cc which is now fixed by using scoped_ptrs in that vector.
>
> BUG=478934
>
> Committed: https://crrev.com/a750e126346aa42df1b0cbc2ae6a58abbe7a5069
> Cr-Commit-Position: refs/heads/master@{#377856}

[email protected],[email protected]
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=478934

Review URL: https://codereview.chromium.org/1745133002

Cr-Commit-Position: refs/heads/master@{#378274}
23 files changed