Bug 1661356 - Change nsLayoutUtils::ComputeScrollMetadata() to take a scrollport size instead of a scrollport rect. r=kats

No one meaningfully uses the scrollport rect's origin, so there's no
point in having callers compute it.

Differential Revision: https://phabricator.services.mozilla.com/D88337

layout/base/nsLayoutUtils.cpp

@@ -9209,7 +9209,7 @@ bool nsLayoutUtils::CanScrollOriginClobberApz(ScrollOrigin aScrollOrigin) {
 ScrollMetadata nsLayoutUtils::ComputeScrollMetadata(
     nsIFrame* aForFrame, nsIFrame* aScrollFrame, nsIContent* aContent,
     const nsIFrame* aReferenceFrame, LayerManager* aLayerManager,
-    ViewID aScrollParentId, const nsRect& aViewport,
+    ViewID aScrollParentId, const nsSize& aScrollPortSize,
     const Maybe<nsRect>& aClipRect, bool aIsRootContent,
     const Maybe<ContainerLayerParameters>& aContainerParameters) {
   nsPresContext* presContext = aForFrame->PresContext();
@@ -9218,7 +9218,8 @@ ScrollMetadata nsLayoutUtils::ComputeScrollMetadata(
   PresShell* presShell = presContext->GetPresShell();
   ScrollMetadata metadata;
   FrameMetrics& metrics = metadata.GetMetrics();
-  metrics.SetLayoutViewport(CSSRect::FromAppUnits(aViewport));
+  metrics.SetLayoutViewport(
+      CSSRect(CSSPoint(), CSSSize::FromAppUnits(aScrollPortSize)));
 
   nsIDocShell* docShell = presContext->GetDocShell();
   BrowsingContext* bc = docShell ? docShell->GetBrowsingContext() : nullptr;
@@ -9640,16 +9641,16 @@ Maybe<ScrollMetadata> nsLayoutUtils::GetRootMetadata(
   if (addMetrics || ensureMetricsForRootId) {
     bool isRootContent = presContext->IsRootContentDocumentCrossProcess();
 
-    nsRect viewport(aBuilder->ToReferenceFrame(frame), frame->GetSize());
+    nsSize scrollPortSize = frame->GetSize();
     if (isRootContent && rootScrollFrame) {
       nsIScrollableFrame* scrollableFrame =
           rootScrollFrame->GetScrollTargetFrame();
-      viewport.SizeTo(scrollableFrame->GetScrollPortRect().Size());
+      scrollPortSize = scrollableFrame->GetScrollPortRect().Size();
     }
     return Some(nsLayoutUtils::ComputeScrollMetadata(
         frame, rootScrollFrame, content, aBuilder->FindReferenceFrameFor(frame),
-        aLayerManager, ScrollableLayerGuid::NULL_SCROLL_ID, viewport, Nothing(),
-        isRootContent, Some(aContainerParameters)));
+        aLayerManager, ScrollableLayerGuid::NULL_SCROLL_ID, scrollPortSize,
+        Nothing(), isRootContent, Some(aContainerParameters)));
   }
 
   return Nothing();

layout/base/nsLayoutUtils.h

@@ -2903,7 +2903,7 @@ class nsLayoutUtils {
       nsIFrame* aForFrame, nsIFrame* aScrollFrame, nsIContent* aContent,
       const nsIFrame* aReferenceFrame,
       mozilla::layers::LayerManager* aLayerManager, ViewID aScrollParentId,
-      const nsRect& aViewport, const mozilla::Maybe<nsRect>& aClipRect,
+      const nsSize& aScrollPortSize, const mozilla::Maybe<nsRect>& aClipRect,
       bool aIsRoot,
       const mozilla::Maybe<ContainerLayerParameters>& aContainerParameters);
 

layout/generic/nsGfxScrollFrame.cpp

@@ -4307,9 +4307,6 @@ Maybe<ScrollMetadata> ScrollFrameHelper::ComputeScrollMetadata(
     return Nothing();
   }
 
-  nsPoint toReferenceFrame =
-      mOuter->GetOffsetToCrossDoc(aContainerReferenceFrame);
-
   Maybe<nsRect> parentLayerClip;
   if (aClip && mAddClipRectToLayer) {
     parentLayerClip = Some(aClip->GetClipRect());
@@ -4320,11 +4317,9 @@ Maybe<ScrollMetadata> ScrollFrameHelper::ComputeScrollMetadata(
 
   MOZ_ASSERT(mScrolledFrame->GetContent());
 
-  nsRect scrollport = mScrollPort + toReferenceFrame;
-
   return Some(nsLayoutUtils::ComputeScrollMetadata(
       mScrolledFrame, mOuter, mOuter->GetContent(), aContainerReferenceFrame,
-      aLayerManager, mScrollParentID, scrollport, parentLayerClip,
+      aLayerManager, mScrollParentID, mScrollPort.Size(), parentLayerClip,
       isRootContent, aParameters));
 }
 

layout/painting/nsDisplayList.cpp

@@ -38,6 +38,7 @@
 #include "mozilla/ViewportUtils.h"
 #include "nsCSSRendering.h"
 #include "nsCSSRenderingGradients.h"
+#include "nsRefreshDriver.h"
 #include "nsRegion.h"
 #include "nsStyleStructInlines.h"
 #include "nsStyleTransformMatrix.h"
@@ -7091,13 +7092,10 @@ LayerState nsDisplayScrollInfoLayer::GetLayerState(
 UniquePtr<ScrollMetadata> nsDisplayScrollInfoLayer::ComputeScrollMetadata(
     LayerManager* aLayerManager,
     const ContainerLayerParameters& aContainerParameters) {
-  nsRect viewport = mScrollFrame->GetRect() - mScrollFrame->GetPosition() +
-                    mScrollFrame->GetOffsetToCrossDoc(ReferenceFrame());
-
   ScrollMetadata metadata = nsLayoutUtils::ComputeScrollMetadata(
       mScrolledFrame, mScrollFrame, mScrollFrame->GetContent(),
-      ReferenceFrame(), aLayerManager, mScrollParentId, viewport, Nothing(),
-      false, Some(aContainerParameters));
+      ReferenceFrame(), aLayerManager, mScrollParentId, mScrollFrame->GetSize(),
+      Nothing(), false, Some(aContainerParameters));
   metadata.GetMetrics().SetIsScrollInfoLayer(true);
   nsIScrollableFrame* scrollableFrame = mScrollFrame->GetScrollTargetFrame();
   if (scrollableFrame) {