Bail out of Page::networkStateChanged if allPages is NULL

R=abarth@chromium.org
BUG=306648

Review URL: https://codereview.chromium.org/30273002

git-svn-id: svn://svn.chromium.org/blink/trunk@160101 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move RefPtr/reference equality operators to Node.h

They're only needed for Node subclasses, and this move avoids confusing
the maintainers of WTF with the details of Core.

R=mikhail.pozdnyakov@intel.com, thakis@chromium.org, tkent@chromium.org

Review URL: https://codereview.chromium.org/29533003

git-svn-id: svn://svn.chromium.org/blink/trunk@160102 bbb929c8-8fbe-4397-9dbb-9b2b20218538