gpu: Disallow use of IOSurfaces for half-float format with swiftshader.

R=kbr@chromium.org

Bug: 998038
Change-Id: Ic31d28938ef205b36657fc7bd297fe8a63d08543
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1798052
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Auto-Submit: Khushal <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#695826}
bool FeatureInfo::IsES3Capable() const {
  if (workarounds_.disable_texture_storage)
    return false;
  if (gl_version_info_)
    return gl_version_info_->is_es3_capable;
  return false;
}

bool FeatureInfo::IsES3Capable() const {
  if (workarounds_.disable_texture_storage)
    return false;
  if (gl_version_info_)
    return gl_version_info_->is_es3_capable;
  return false;
}
