Bug 1641246 - Remove nsDisplayResolution. r=botond

Differential Revision: https://phabricator.services.mozilla.com/D77111

gfx/layers/Layers.h

@@ -2428,7 +2428,7 @@ class ContainerLayer : public Layer {
   // be part of mTransform.
   float mInheritedXScale;
   float mInheritedYScale;
-  // For layers corresponding to an nsDisplayResolution, the resolution of the
+  // For layers corresponding to an nsDisplayAsyncZoom, the resolution of the
   // associated pres shell; for other layers, 1.0.
   float mPresShellResolution;
   bool mUseIntermediateSurface;

layout/base/PresShell.cpp

@@ -5297,21 +5297,6 @@ void PresShell::SetRenderingState(const RenderingState& aState) {
     }
   }
 
-  // nsSubDocumentFrame uses a resolution different from 1.0 to determine if it
-  // needs to build a nsDisplayResolution item. So if we are going from or
-  // to 1.0 then we need to invalidate the subdoc frame so that item gets
-  // created/removed.
-  if (mResolution.valueOr(1.0) != aState.mResolution.valueOr(1.0) &&
-      (mResolution.valueOr(1.0) == 1.0 ||
-       aState.mResolution.valueOr(1.0) == 1.0)) {
-    if (nsIFrame* frame = GetRootFrame()) {
-      frame = nsLayoutUtils::GetCrossDocParentFrame(frame);
-      if (frame) {
-        frame->InvalidateFrame();
-      }
-    }
-  }
-
   mRenderingStateFlags = aState.mRenderingStateFlags;
   mResolution = aState.mResolution;
 }

layout/generic/nsSubDocumentFrame.cpp

@@ -431,12 +431,9 @@ void nsSubDocumentFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
   clipState.ClipContainingBlockDescendantsToContentBox(aBuilder, this);
 
   nsIScrollableFrame* sf = presShell->GetRootScrollFrameAsScrollable();
-  bool constructResolutionItem =
-      subdocRootFrame && (presShell->GetResolution() != 1.0);
   bool constructZoomItem = subdocRootFrame && parentAPD != subdocAPD;
   bool needsOwnLayer = false;
-  if (constructResolutionItem || constructZoomItem ||
+  if (constructZoomItem || presContext->IsRootContentDocument() ||
-      presContext->IsRootContentDocument() ||
       (sf && sf->IsScrollingActive(aBuilder))) {
     needsOwnLayer = true;
   }
@@ -525,7 +522,7 @@ void nsSubDocumentFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
   // becomes the topmost. We do this below.
   if (constructZoomItem) {
     nsDisplayOwnLayerFlags zoomFlags = flags;
-    if (ignoreViewportScrolling && !constructResolutionItem) {
+    if (ignoreViewportScrolling) {
       zoomFlags |= nsDisplayOwnLayerFlags::GenerateScrollableLayer;
     }
     childItems.AppendNewToTop<nsDisplayZoom>(aBuilder, subdocRootFrame, this,
@@ -540,12 +537,6 @@ void nsSubDocumentFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
   if (ignoreViewportScrolling) {
     flags |= nsDisplayOwnLayerFlags::GenerateScrollableLayer;
   }
-  if (constructResolutionItem) {
-    childItems.AppendNewToTop<nsDisplayResolution>(aBuilder, subdocRootFrame,
-                                                   this, &childItems, flags);
-
-    needsOwnLayer = false;
-  }
 
   // We always want top level content documents to be in their own layer.
   nsDisplaySubDocument* layerItem = MakeDisplayItem<nsDisplaySubDocument>(

layout/painting/nsDisplayItemTypesList.h

@@ -65,8 +65,6 @@ DECLARE_DISPLAY_ITEM_TYPE(PLUGIN_READBACK, 0)
 DECLARE_DISPLAY_ITEM_TYPE(PRINT_PLUGIN, 0)
 DECLARE_DISPLAY_ITEM_TYPE(RANGE_FOCUS_RING, 0)
 DECLARE_DISPLAY_ITEM_TYPE(REMOTE, TYPE_RENDERS_NO_IMAGES)
-DECLARE_DISPLAY_ITEM_TYPE(RESOLUTION,
-                          TYPE_RENDERS_NO_IMAGES | TYPE_IS_CONTAINER)
 DECLARE_DISPLAY_ITEM_TYPE(SCROLL_INFO_LAYER,
                           TYPE_RENDERS_NO_IMAGES | TYPE_IS_CONTAINER)
 DECLARE_DISPLAY_ITEM_TYPE(SELECTION_OVERLAY, TYPE_RENDERS_NO_IMAGES)

layout/painting/nsDisplayList.cpp

@@ -6548,29 +6548,6 @@ nsRegion nsDisplaySubDocument::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
   return nsDisplayOwnLayer::GetOpaqueRegion(aBuilder, aSnap);
 }
 
-nsDisplayResolution::nsDisplayResolution(nsDisplayListBuilder* aBuilder,
-                                         nsIFrame* aFrame,
-                                         nsSubDocumentFrame* aSubDocFrame,
-                                         nsDisplayList* aList,
-                                         nsDisplayOwnLayerFlags aFlags)
-    : nsDisplaySubDocument(aBuilder, aFrame, aSubDocFrame, aList, aFlags) {
-  MOZ_COUNT_CTOR(nsDisplayResolution);
-}
-
-already_AddRefed<Layer> nsDisplayResolution::BuildLayer(
-    nsDisplayListBuilder* aBuilder, LayerManager* aManager,
-    const ContainerLayerParameters& aContainerParameters) {
-  float rootLayerResolution = 1.0f;
-  ContainerLayerParameters containerParameters(
-      rootLayerResolution, rootLayerResolution, nsIntPoint(),
-      aContainerParameters);
-
-  RefPtr<Layer> layer =
-      nsDisplaySubDocument::BuildLayer(aBuilder, aManager, containerParameters);
-
-  return layer.forget();
-}
-
 /* static */
 nsDisplayFixedPosition* nsDisplayFixedPosition::CreateForFixedBackground(
     nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, nsIFrame* aSecondaryFrame,

layout/painting/nsDisplayList.h

@@ -6107,25 +6107,6 @@ class nsDisplaySubDocument : public nsDisplayOwnLayer {
   nsSubDocumentFrame* mSubDocFrame;
 };
 
-/**
- * A display item for subdocuments to capture the resolution from the presShell
- * and ensure that it gets applied to all the right elements. This item creates
- * a container layer.
- */
-class nsDisplayResolution : public nsDisplaySubDocument {
- public:
-  nsDisplayResolution(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
-                      nsSubDocumentFrame* aSubDocFrame, nsDisplayList* aList,
-                      nsDisplayOwnLayerFlags aFlags);
-  MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayResolution)
-
-  NS_DISPLAY_DECL_NAME("Resolution", TYPE_RESOLUTION)
-
-  already_AddRefed<Layer> BuildLayer(
-      nsDisplayListBuilder* aBuilder, LayerManager* aManager,
-      const ContainerLayerParameters& aContainerParameters) override;
-};
-
 /**
  * A display item used to represent sticky position elements. The contents
  * gets its own layer and creates a stacking context, and the layer will have