WebRenderApi.cpp

void DisplayListBuilder::PushShadow(const wr::LayoutRect& aRect,
                                    const wr::LayoutRect& aClip,
                                    bool aIsBackfaceVisible,
                                    const wr::Shadow& aShadow) {
  // Local clip_rects are translated inside of shadows, as they are assumed to
  // be part of the element drawing itself, and not a parent frame clipping it.
  // As such, it is not sound to apply the MergeClipLeaf optimization inside of
  // shadows. So we disable the optimization when we encounter a shadow.
  // Shadows don't span frames, so we don't have to worry about MergeClipLeaf
  // being re-enabled mid-shadow. The optimization is restored in PopAllShadows.
  SuspendClipLeafMerging();
  wr_dp_push_shadow(mWrState, aRect, aClip, aIsBackfaceVisible,
                    &mCurrentSpaceAndClipChain, aShadow);
}

void DisplayListBuilder::PopAllShadows() {
  wr_dp_pop_all_shadows(mWrState);
  ResumeClipLeafMerging();
}