Bug 1269935 - Replace PresShell::DecVisibleCount() with a general map function. r=mstange

layout/base/nsPresShell.cpp

@@ -5745,18 +5745,17 @@ PresShell::MarkFramesInListApproximatelyVisible(const nsDisplayList& aList)
   }
 }
 
-/* static */ void
-PresShell::DecVisibleCount(const VisibleFrames& aFrames,
-                           VisibilityCounter aCounter,
-                           Maybe<OnNonvisible> aNonvisibleAction /* = Nothing() */)
+template <typename Func> void
+ForAllTrackedFramesInVisibleSet(const VisibleFrames& aFrames, Func aFunc)
 {
   for (auto iter = aFrames.ConstIter(); !iter.Done(); iter.Next()) {
     nsIFrame* frame = iter.Get()->GetKey();
-    // Decrement the frame's visible count if we're still tracking its
-    // visibility. (We may not be, if the frame disabled visibility tracking
-    // after we added it to the visible frames list.)
+
+    // Call |aFunc| if we're still tracking the frame's visibility. (We may
+    // not be, if the frame disabled visibility tracking after we added it to
+    // the visible frames list.)
     if (frame->TrackingVisibility()) {
-      frame->DecVisibilityCount(aCounter, aNonvisibleAction);
+      aFunc(frame);
     }
   }
 }
@@ -5801,8 +5800,9 @@ PresShell::RebuildApproximateFrameVisibilityDisplayList(const nsDisplayList& aLi
 
   MarkFramesInListApproximatelyVisible(aList);
 
-  DecVisibleCount(oldApproximatelyVisibleFrames,
-                  VisibilityCounter::MAY_BECOME_VISIBLE);
+  ForAllTrackedFramesInVisibleSet(oldApproximatelyVisibleFrames, [&](nsIFrame* aFrame) {
+    aFrame->DecVisibilityCount(VisibilityCounter::MAY_BECOME_VISIBLE);
+  });
 
   NotifyCompositorOfVisibleRegionsChange();
 }
@@ -5827,14 +5827,14 @@ void
 PresShell::ClearVisibleFramesSets(Maybe<OnNonvisible> aNonvisibleAction
                                     /* = Nothing() */)
 {
-  DecVisibleCount(mApproximatelyVisibleFrames,
-                  VisibilityCounter::MAY_BECOME_VISIBLE,
-                  aNonvisibleAction);
-  mApproximatelyVisibleFrames.Clear();
+  ForAllTrackedFramesInVisibleSet(mApproximatelyVisibleFrames, [&](nsIFrame* aFrame) {
+    aFrame->DecVisibilityCount(VisibilityCounter::MAY_BECOME_VISIBLE, aNonvisibleAction);
+  });
+  ForAllTrackedFramesInVisibleSet(mInDisplayPortFrames, [&](nsIFrame* aFrame) {
+    aFrame->DecVisibilityCount(VisibilityCounter::IN_DISPLAYPORT, aNonvisibleAction);
+  });
 
-  DecVisibleCount(mInDisplayPortFrames,
-                  VisibilityCounter::IN_DISPLAYPORT,
-                  aNonvisibleAction);
+  mApproximatelyVisibleFrames.Clear();
   mInDisplayPortFrames.Clear();
 
   if (mVisibleRegions) {
@@ -5962,8 +5962,9 @@ PresShell::RebuildApproximateFrameVisibility(nsRect* aRect,
 
   MarkFramesInSubtreeApproximatelyVisible(rootFrame, vis, aRemoveOnly);
 
-  DecVisibleCount(oldApproximatelyVisibleFrames,
-                  VisibilityCounter::MAY_BECOME_VISIBLE);
+  ForAllTrackedFramesInVisibleSet(oldApproximatelyVisibleFrames, [&](nsIFrame* aFrame) {
+    aFrame->DecVisibilityCount(VisibilityCounter::MAY_BECOME_VISIBLE);
+  });
 
   NotifyCompositorOfVisibleRegionsChange();
 }
@@ -6403,7 +6404,9 @@ PresShell::Paint(nsView*        aViewToPaint,
     nsLayoutUtils::PaintFrame(nullptr, frame, aDirtyRegion, bgcolor,
                               nsDisplayListBuilderMode::PAINTING, flags);
 
-    DecVisibleCount(oldInDisplayPortFrames, VisibilityCounter::IN_DISPLAYPORT);
+    ForAllTrackedFramesInVisibleSet(oldInDisplayPortFrames, [&](nsIFrame* aFrame) {
+      aFrame->DecVisibilityCount(VisibilityCounter::IN_DISPLAYPORT);
+    });
 
     if (mVisibleRegions &&
         !mNotifyCompositorOfVisibleRegionsChangeEvent.IsPending()) {

layout/base/nsPresShell.h

@@ -777,10 +777,6 @@ protected:
                                                const nsRect& aRect,
                                                bool aRemoveOnly = false);
 
-  void DecVisibleCount(const VisibleFrames& aFrames,
-                       VisibilityCounter aCounter,
-                       Maybe<OnNonvisible> aNonvisibleAction = Nothing());
-
   void InitVisibleRegionsIfVisualizationEnabled(VisibilityCounter aForCounter);
   void AddFrameToVisibleRegions(nsIFrame* aFrame, VisibilityCounter aForCounter);
   void NotifyCompositorOfVisibleRegionsChange();