Remove StyleImage::SetIsLazyloadPossiblyDeferred

The only time when this is used is to set the value to true on a
StylePendingImage. The StylePendingImage is never read from or used
except for getting the underlying CSSValue though, making the store dead
and the method unused.
Also remove the cast from StyleImage to StyleFetchedImage, which is
unnecessary because the flag lives in the base class (StyleImage) and
is only set by the subclass constructors.

Change-Id: Idc899bc050ae3a7266df311279378e932194189d
Reviewed-on: https://chromium-review.googlesource.com/1213147
Reviewed-by: rajendrant <rajendrant@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#590971}
2 files changed