commit cd80804c61b6d9578a633d3546043d03aecdf27b
author yosin <yosin@chromium.org> Thu Jul 07 04:41:48 2016
committer Commit bot <commit-bot@chromium.org> Thu Jul 07 04:43:56 2016
tree d0b4fff6f29f8b8c586a17906b2f13ed393d79d5
parent 14b4d7e08c4ff427b6db64d795c1768f860cbb56

Make ReplaceSelectionCommand to handle empty SPAN replacement

This patch makes |ReplaceSelectionCommand| to handle empty SPAN replacement.

Before this patch, it crashes at |SimplifyMarkupCommand::doApply()| with
null pointer reference passed by |ReplaceSelectionCommand| with
null |insertNodes.firstNodeInserted()|.

BUG=619131
TEST=run_webkit_unit_tests --gtest_filter=ReplaceSelectionCommandTest.pastingEmptySpan

Review-Url: https://codereview.chromium.org/2122003003
Cr-Commit-Position: refs/heads/master@{#404075}