Use hasSelection() instead of mHasSelection

We should be using the getter method, hasSelection() instead of accessing
the mHasSelection directly. This will make things simpler in
crrev.com/2785853002 when hasSelection() will do something more
complicated than returning a boolean field.

BUG=627234

Review-Url: https://codereview.chromium.org/2904033002
Cr-Commit-Position: refs/heads/master@{#474739}
1 file changed