Clean up NavigationControllerImpl::IsURLInPageNavigation

IsURLInPageNavigation was incorrectly being called twice.  This led to
duplicate attempts to try to kill the renderer process when it failed,
and it ran in slightly different states each time.  This CL ensures we
only call it once in the correct state.

BUG=618104
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2376643002
Cr-Commit-Position: refs/heads/master@{#421557}

diff --git a/AUTHORS b/AUTHORS
index 7ad2718..a933b97 100644
--- a/AUTHORS
+++ b/AUTHORS

@@ -755,6 +755,7 @@
 Cathie Chen <cathiechen@tencent.com>
 Kyle Plumadore <kyle.plumadore@amd.com>
 Sunchang Li <johnstonli@tencent.com>
+Yeol Park <peary2@gmail.com>
 
 BlackBerry Limited <*@blackberry.com>
 Code Aurora Forum <*@codeaurora.org>