Cleanup/Renaming in preparation for larger refactoring

* Added name for wallpaper widget
* Renamed EndPendingAnimation to StopAnimating
* Renamed WallpaperWidgetController::property to GetWallpaperProperty().
  (It'll be delegated to wallpaper view in next CL).
* Added WallpaperView::proeprty(), instead of returning blur_sigma/opacity separately.

Bug: None
Test: None
Change-Id: Ic8aa86990a45e6a99472733f4949861be22dd89e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1973963
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726026}
12 files changed