Rename PageActionIconView::UpdateIcon() to UpdateIconImage()

This rename helps disambiguate Update() and UpdateIcon() by renaming the
latter as UpdateIconImage().
The former updates the view's visibility state while the latter updates
the vector icon used by painting.

Bug: 788051
Change-Id: I1a6d24ed404b5a2017e64ea9b064ada6de7865dd
Reviewed-on: https://chromium-review.googlesource.com/1088453
Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565136}
4 files changed