Add IsRestored() interface to NavigationEntry and use it to differentiate
normal and restored synced navigations.

BUG=340464

Review URL: https://codereview.chromium.org/152233003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249526 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249526