Restore overwriting of this._sourceBrowser as it was before bug 1308621
to ensure we continue to use the same DOM to do print previewing (and
eventually printing).
Bug 1308621 already changed the enterPrintPreview code to rely on the
member _sourceBrowser variable, which will be updated to point to the
print preview browser if/when print preview is being reinitialized for
the same page (because one of the print settings changes). We need to
do this to avoid re-initializing off the original browser, which may
now have navigated or be displaying something else entirely.
This also updates the 'simplified' mode code to rely on the extant
_originalURL member to avoid displaying the page URL as about:blank
after a settings change.
MozReview-Commit-ID: DZ1kT7Mb0mS
--HG--
extra : rebase_source : cb79c835d6f8bcd67a7118de3a19b1cab85b6593
42e1871519