From fe4c928a464b5a53c3f8d8335663c4276648e30f Mon Sep 17 00:00:00 2001
From: Simon Giesecke <sgiesecke@mozilla.com>
Date: Tue, 5 May 2020 10:05:59 +0000
Subject: [PATCH] Bug 1626570 - Improve handling of copying arrays in
 layout/painting/. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D72352
---
 layout/painting/DisplayItemClip.h             | 2 +-
 layout/painting/FrameLayerBuilder.cpp         | 4 ++--
 layout/painting/MaskLayerImageCache.cpp       | 3 ++-
 layout/painting/nsDisplayList.h               | 7 ++++---
 layout/painting/nsDisplayListInvalidation.cpp | 2 +-
 5 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/layout/painting/DisplayItemClip.h b/layout/painting/DisplayItemClip.h
index bd658eb61586..ff9df266035d 100644
--- a/layout/painting/DisplayItemClip.h
+++ b/layout/painting/DisplayItemClip.h
@@ -182,7 +182,7 @@ class DisplayItemClip {
 
  private:
   nsRect mClipRect;
-  nsTArray<RoundedRect> mRoundedClipRects;
+  CopyableTArray<RoundedRect> mRoundedClipRects;
   // If mHaveClipRect is false then this object represents no clipping at all
   // and mRoundedClipRects must be empty.
   bool mHaveClipRect;
diff --git a/layout/painting/FrameLayerBuilder.cpp b/layout/painting/FrameLayerBuilder.cpp
index faf1fd6c0fef..4d6cb1936214 100644
--- a/layout/painting/FrameLayerBuilder.cpp
+++ b/layout/painting/FrameLayerBuilder.cpp
@@ -333,7 +333,7 @@ void DisplayItemData::BeginUpdate(Layer* aLayer, LayerState aState,
 
   // We avoid adding or removing element unnecessarily
   // since we have to modify userdata each time
-  AutoTArray<nsIFrame*, 4> copy(mFrameList);
+  CopyableAutoTArray<nsIFrame*, 4> copy(mFrameList);
   if (!copy.RemoveElement(aItem->Frame())) {
     AddFrame(aItem->Frame());
     mChangedFrameInvalidations.Or(mChangedFrameInvalidations,
@@ -5740,7 +5740,7 @@ void ContainerState::SetupScrollingMetadata(NewLayerEntry* aEntry) {
   // so add to it rather than overwriting it (we clear the list when recycling
   // a layer).
   nsTArray<RefPtr<Layer>> maskLayers(
-      aEntry->mLayer->GetAllAncestorMaskLayers());
+      aEntry->mLayer->GetAllAncestorMaskLayers().Clone());
 
   // Iterate over the ASR chain and create the corresponding scroll metadatas.
   // This loop is slightly tricky because the scrollframe-to-clip relationship
diff --git a/layout/painting/MaskLayerImageCache.cpp b/layout/painting/MaskLayerImageCache.cpp
index e93d87d107c0..2b3b63dc5750 100644
--- a/layout/painting/MaskLayerImageCache.cpp
+++ b/layout/painting/MaskLayerImageCache.cpp
@@ -52,7 +52,8 @@ MaskLayerImageCache::MaskLayerImageKey::MaskLayerImageKey()
 
 MaskLayerImageCache::MaskLayerImageKey::MaskLayerImageKey(
     const MaskLayerImageKey& aKey)
-    : mRoundedClipRects(aKey.mRoundedClipRects), mLayerCount(aKey.mLayerCount) {
+    : mRoundedClipRects(aKey.mRoundedClipRects.Clone()),
+      mLayerCount(aKey.mLayerCount) {
   MOZ_COUNT_CTOR(MaskLayerImageKey);
 }
 
diff --git a/layout/painting/nsDisplayList.h b/layout/painting/nsDisplayList.h
index 2579b6967451..b15224dd0473 100644
--- a/layout/painting/nsDisplayList.h
+++ b/layout/painting/nsDisplayList.h
@@ -5383,7 +5383,7 @@ class nsDisplayWrapList : public nsDisplayHitTestInfoBase {
       : nsDisplayHitTestInfoBase(aBuilder, aOther),
         mListPtr(&mList),
         mFrameActiveScrolledRoot(aOther.mFrameActiveScrolledRoot),
-        mMergedFrames(aOther.mMergedFrames),
+        mMergedFrames(aOther.mMergedFrames.Clone()),
         mBounds(aOther.mBounds),
         mBaseBuildingRect(aOther.mBaseBuildingRect),
         mOverrideZIndex(aOther.mOverrideZIndex),
@@ -5567,7 +5567,7 @@ class nsDisplayWrapList : public nsDisplayHitTestInfoBase {
     buildingRect.UnionRect(GetBuildingRect(), aOther->GetBuildingRect());
     SetBuildingRect(buildingRect);
     mMergedFrames.AppendElement(aOther->mFrame);
-    mMergedFrames.AppendElements(aOther->mMergedFrames);
+    mMergedFrames.AppendElements(aOther->mMergedFrames.Clone());
   }
 
   RetainedDisplayList mList;
@@ -6598,7 +6598,8 @@ class nsDisplayMasksAndClipPaths : public nsDisplayEffectsBase {
                              const ActiveScrolledRoot* aActiveScrolledRoot);
   nsDisplayMasksAndClipPaths(nsDisplayListBuilder* aBuilder,
                              const nsDisplayMasksAndClipPaths& aOther)
-      : nsDisplayEffectsBase(aBuilder, aOther), mDestRects(aOther.mDestRects) {
+      : nsDisplayEffectsBase(aBuilder, aOther),
+        mDestRects(aOther.mDestRects.Clone()) {
     MOZ_COUNT_CTOR(nsDisplayMasksAndClipPaths);
   }
 
diff --git a/layout/painting/nsDisplayListInvalidation.cpp b/layout/painting/nsDisplayListInvalidation.cpp
index 02c16e32182c..a7a80519969f 100644
--- a/layout/painting/nsDisplayListInvalidation.cpp
+++ b/layout/painting/nsDisplayListInvalidation.cpp
@@ -107,7 +107,7 @@ nsDisplayMasksAndClipPathsGeometry::nsDisplayMasksAndClipPathsGeometry(
     nsDisplayMasksAndClipPaths* aItem, nsDisplayListBuilder* aBuilder)
     : nsDisplaySVGEffectGeometry(aItem, aBuilder),
       nsImageGeometryMixin(aItem, aBuilder),
-      mDestRects(aItem->GetDestRects()) {}
+      mDestRects(aItem->GetDestRects().Clone()) {}
 
 nsDisplayFiltersGeometry::nsDisplayFiltersGeometry(
     nsDisplayFilters* aItem, nsDisplayListBuilder* aBuilder)