Bug 1539238 - Modify nsSHEntry::Create to consolidate setter calls on nsSHEntry in nsDocShell::AddToSessionHistory, r=peterv

nsDocShell is the only consumer of nsISHEntry::Create, and
in AddToSessionHistory method, after calling nsISHEntry::Create,
it calls 8 setter methods on nsISHEntry, which results in a
total of 9 sync IPC calls.

With the proposed solution of setting everything via
nsISHEntry::Create, we get a total of 1 sync IPC call.

Differential Revision: https://phabricator.services.mozilla.com/D24979

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extra : rebase_source : af9c75043260a6333d789d3ca882173703f7bc29
extra : amend_source : 334281153e24f9e9f0abac3983d32fb99dae6995
extra : source : a8eed7c5d12c49366ad8acd706fa0e8464ed8549
extra : histedit_source : 653daabf83d43571803a1e33c95a4804e4275e7d