Hide the More... button in the query control if there isn't any "more" params to display.
Hide the More... button in the query control if there isn't any "more" params to display.

BUG=skia:
TBR=stephana

Review URL: https://codereview.chromium.org/923613002

google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot