The length of a TextIterator containing replaced element is at least 1

When a TextIterator is created for a range that contains a replaced
element then one ',' (comma) will surely be emitted. This way the
length of the created TextIterator will be at least 1. In spite of
this, the WebCore::PlainTextRange::createRangeFor method assumes that
the length of the iterator only can be one if that one character is a
newline. The patch fixes this wrong assumption.

R=tkent@chromium.org
BUG=385630

Review URL: https://codereview.chromium.org/342483002

git-svn-id: svn://svn.chromium.org/blink/trunk@177130 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Unflaky test inspector/timeline/timeline-network-received-data.html

It was a race between the event arrived into timeline and the script that was evaluated in the page.

BUG=316150

Review URL: https://codereview.chromium.org/351873003

git-svn-id: svn://svn.chromium.org/blink/trunk@177131 bbb929c8-8fbe-4397-9dbb-9b2b20218538