Rejecting a modified form close confirmation warning has different results depending on how window is closed
This is sort of a continuation from #1445 (closed). Open a tab on a website with a form and paste a bunch of data into the form, enough to trigger the modified form close confirmation warning. Then attempt to close the window using the close button in the header bar. Reject the confirmation dialog to continue using Epiphany, then open another tab foo.com, then attempt to close the window again, and this time accept the close confirmation warning to really close Epiphany. Reopen Epiphany and both your original session and foo.com are there.
Now repeat the above process using Ctrl+Q rather than the close button in the header bar, and foo.com is missing when you reopen Epiphany, because the session got closed in ephy_shell_close_all_windows() before the modified form confirmation warning ever ran. This is inconsistent and bad. I think we can probably just remove the call to ephy_session_close() from ephy_shell_close_all_windows(), but I wonder if I am missing something.