Make TextMatchMarkers constructible in single step

Currently, we only construct instances of TextMatchMarker (previously
RenderedDocumentMarker) inside TextMatchMarkerListImpl, by calling
TextMatchMarker::Create() on an instance of DocumentMarker. This CL changes this
so callers directly construct instances of TextMatchMarker. This sets us up to
eventually move the storage and accessor methods for whether or not the marker
is active out of DocumentMarker and into TextMatchMarker.

BUG=707867

Review-Url: https://codereview.chromium.org/2905753002
Cr-Commit-Position: refs/heads/master@{#475724}
6 files changed