Bug 1300864 - Disable paint skipping for scroll frames that contain out-of-flow content inside a CSS filter. r=mstange

MozReview-Commit-ID: 5TwC75wzOsm

--HG--
extra : rebase_source : 2c38372e452cf6b78b4906b42e4b9e93a1762d26

layout/generic/nsFrame.cpp

@@ -2936,6 +2936,8 @@ nsIFrame::BuildDisplayListForStackingContext(nsDisplayListBuilder* aBuilder,
       inTransformSetter(aBuilder, inTransform);
     nsDisplayListBuilder::AutoSaveRestorePerspectiveIndex
       perspectiveIndex(aBuilder, this);
+    nsDisplayListBuilder::AutoFilterASRSetter
+      filterASRSetter(aBuilder, usingFilter);
 
     CheckForApzAwareEventHandlers(aBuilder, this);
 

layout/generic/nsGfxScrollFrame.cpp

@@ -1301,6 +1301,12 @@ ScrollFrameHelper::SetZoomableByAPZ(bool aZoomable)
   }
 }
 
+void
+ScrollFrameHelper::SetHasOutOfFlowContentInsideFilter()
+{
+  mHasOutOfFlowContentInsideFilter = true;
+}
+
 bool
 ScrollFrameHelper::WantAsyncScroll() const
 {
@@ -2075,6 +2081,7 @@ ScrollFrameHelper::ScrollFrameHelper(nsContainerFrame* aOuter,
   , mTransformingByAPZ(false)
   , mScrollableByAPZ(false)
   , mZoomableByAPZ(false)
+  , mHasOutOfFlowContentInsideFilter(false)
   , mSuppressScrollbarRepaints(false)
   , mVelocityQueue(aOuter->PresContext())
 {
@@ -2879,13 +2886,15 @@ ScrollFrameHelper::ScrollToImpl(nsPoint aPt, const nsRect& aRange, nsAtom* aOrig
       nsLayoutUtils::GetHighResolutionDisplayPort(content, &displayPort);
     displayPort.MoveBy(-mScrolledFrame->GetPosition());
 
-    PAINT_SKIP_LOG("New scrollpos %s usingDP %d dpEqual %d scrollableByApz %d plugins %d perspective %d bglocal %d\n",
+    PAINT_SKIP_LOG("New scrollpos %s usingDP %d dpEqual %d scrollableByApz %d plugins"
+        "%d perspective %d bglocal %d filter %d\n",
         Stringify(CSSPoint::FromAppUnits(GetScrollPosition())).c_str(),
         usingDisplayPort, displayPort.IsEqualEdges(oldDisplayPort),
         mScrollableByAPZ, HasPluginFrames(), HasPerspective(),
-        HasBgAttachmentLocal());
+        HasBgAttachmentLocal(), mHasOutOfFlowContentInsideFilter);
     if (usingDisplayPort && displayPort.IsEqualEdges(oldDisplayPort) &&
-        !HasPerspective() && !HasBgAttachmentLocal()) {
+        !HasPerspective() && !HasBgAttachmentLocal() &&
+        !mHasOutOfFlowContentInsideFilter) {
       bool haveScrollLinkedEffects = content->GetComposedDoc()->HasScrollLinkedEffect();
       bool apzDisabled = haveScrollLinkedEffects && gfxPrefs::APZDisableForScrollLinkedEffects();
       if (!apzDisabled && !HasPluginFrames()) {

layout/generic/nsGfxScrollFrame.h

@@ -426,6 +426,7 @@ public:
   }
   void SetScrollableByAPZ(bool aScrollable);
   void SetZoomableByAPZ(bool aZoomable);
+  void SetHasOutOfFlowContentInsideFilter();
 
   bool UsesContainerScrolling() const;
 
@@ -632,6 +633,10 @@ public:
   // True if the APZ is allowed to zoom this scrollframe.
   bool mZoomableByAPZ:1;
 
+  // True if the scroll frame contains out-of-flow content and is inside
+  // a CSS filter.
+  bool mHasOutOfFlowContentInsideFilter:1;
+
   // True if we don't want the scrollbar to repaint itself right now.
   bool mSuppressScrollbarRepaints:1;
 
@@ -1062,6 +1067,9 @@ public:
   void SetZoomableByAPZ(bool aZoomable) override {
     mHelper.SetZoomableByAPZ(aZoomable);
   }
+  void SetHasOutOfFlowContentInsideFilter() override {
+    mHelper.SetHasOutOfFlowContentInsideFilter();
+  }
 
   ScrollSnapInfo GetScrollSnapInfo() const override {
     return mHelper.GetScrollSnapInfo();
@@ -1497,6 +1505,9 @@ public:
   void SetZoomableByAPZ(bool aZoomable) override {
     mHelper.SetZoomableByAPZ(aZoomable);
   }
+  void SetHasOutOfFlowContentInsideFilter() override {
+    mHelper.SetHasOutOfFlowContentInsideFilter();
+  }
   virtual bool DecideScrollableLayer(nsDisplayListBuilder* aBuilder,
                                      nsRect* aVisibleRect,
                                      nsRect* aDirtyRect,

layout/generic/nsIScrollableFrame.h

@@ -448,6 +448,13 @@ public:
    */
   virtual void SetZoomableByAPZ(bool aZoomable) = 0;
 
+  /**
+   * Mark this scroll frame as having out-of-flow content inside a CSS filter.
+   * Such content will move incorrectly during async-scrolling; to mitigate
+   * this, paint skipping is disabled for such scroll frames.
+   */
+  virtual void SetHasOutOfFlowContentInsideFilter() = 0;
+
   /**
    * Whether or not this frame uses containerful scrolling.
    */

layout/painting/nsDisplayList.cpp

@@ -919,6 +919,17 @@ nsDisplayListBuilder::AutoCurrentActiveScrolledRootSetter::SetCurrentActiveScrol
   mBuilder->mCurrentContainerASR = ActiveScrolledRoot::PickAncestor(
     mBuilder->mCurrentContainerASR, finiteBoundsASR);
 
+  // If we are entering out-of-flow content inside a CSS filter, mark
+  // scroll frames wrt. which the content is fixed as containing such content.
+  if (mBuilder->mFilterASR &&
+      ActiveScrolledRoot::IsAncestor(aActiveScrolledRoot, mBuilder->mFilterASR)) {
+    for (const ActiveScrolledRoot* asr = mBuilder->mFilterASR;
+         asr && asr != aActiveScrolledRoot;
+         asr = asr->mParent) {
+      asr->mScrollableFrame->SetHasOutOfFlowContentInsideFilter();
+    }
+  }
+
   mUsed = true;
 }
 
@@ -970,6 +981,7 @@ nsDisplayListBuilder::nsDisplayListBuilder(nsIFrame* aReferenceFrame,
       mCurrentScrollbarFlags(nsDisplayOwnLayerFlags::eNone),
       mPerspectiveItemIndex(0),
       mSVGEffectsBuildingDepth(0),
+      mFilterASR(nullptr),
       mContainsBlendMode(false),
       mIsBuildingScrollbar(false),
       mCurrentScrollbarWillHaveLayer(false),

layout/painting/nsDisplayList.h

@@ -1125,6 +1125,28 @@ public:
     bool                  mOldValue;
   };
 
+  /**
+   * A helper class to temporarily set the value of mFilterASR.
+   */
+  class AutoFilterASRSetter;
+  friend class AutoFilterASRSetter;
+  class AutoFilterASRSetter {
+  public:
+    AutoFilterASRSetter(nsDisplayListBuilder* aBuilder, bool aUsingFilter)
+      : mBuilder(aBuilder), mOldValue(aBuilder->mFilterASR)
+    {
+      if (!aBuilder->mFilterASR && aUsingFilter) {
+        aBuilder->mFilterASR = aBuilder->CurrentActiveScrolledRoot();
+      }
+    }
+    ~AutoFilterASRSetter() {
+      mBuilder->mFilterASR = mOldValue;
+    }
+  private:
+    nsDisplayListBuilder* mBuilder;
+    const ActiveScrolledRoot* mOldValue;
+  };
+
   class AutoSaveRestorePerspectiveIndex;
   friend class AutoSaveRestorePerspectiveIndex;
   class AutoSaveRestorePerspectiveIndex {
@@ -1771,6 +1793,9 @@ private:
   Preserves3DContext             mPreserves3DCtx;
   uint32_t                       mPerspectiveItemIndex;
   int32_t                        mSVGEffectsBuildingDepth;
+  // When we are inside a filter, the current ASR at the time we entered the
+  // filter. Otherwise nullptr.
+  const ActiveScrolledRoot*      mFilterASR;
   bool                           mContainsBlendMode;
   bool                           mIsBuildingScrollbar;
   bool                           mCurrentScrollbarWillHaveLayer;