From a7bbcb15308f6c0bbf525bf7db483bdacb8432a2 Mon Sep 17 00:00:00 2001
From: Robert O'Callahan <robert@ocallahan.org>
Date: Mon, 9 Jun 2014 16:47:59 +1200
Subject: [PATCH] Bug 1022612. Part 8: nsDisplayWrapList (but not subclasses)
 should return true for ShouldFlattenAway. r=mattwoodrow

Also the assertion in TryMerge is going away because we're going to do TryMerge
first in FrameLayerBuilder.

--HG--
extra : rebase_source : d6343f0a7cb26f9848c2d2b8d46bb1787d3ae632
---
 layout/base/nsDisplayList.h         | 16 +++++++++++++++-
 layout/forms/nsSelectsAreaFrame.cpp |  3 +++
 layout/xul/nsBoxFrame.cpp           |  3 +++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/layout/base/nsDisplayList.h b/layout/base/nsDisplayList.h
index 714fc07ac6d..f3ca92732f5 100644
--- a/layout/base/nsDisplayList.h
+++ b/layout/base/nsDisplayList.h
@@ -2619,13 +2619,15 @@ public:
                                  nsRegion* aVisibleRegion,
                                  const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
   virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE {
-    NS_WARNING("This list should already have been flattened!!!");
     return false;
   }
   virtual void GetMergedFrames(nsTArray<nsIFrame*>* aFrames) MOZ_OVERRIDE
   {
     aFrames->AppendElements(mMergedFrames);
   }
+  virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) {
+    return true;
+  }
   virtual bool IsInvalid(nsRect& aRect) MOZ_OVERRIDE
   {
     if (mFrame->IsInvalid(aRect) && aRect.IsEmpty()) {
@@ -2798,6 +2800,9 @@ public:
                                  nsRegion* aVisibleRegion,
                                  const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;
   virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE;
+  virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE {
+    return false;
+  }
   NS_DISPLAY_DECL_NAME("MixBlendMode", TYPE_MIX_BLEND_MODE)
 };
 
@@ -2825,6 +2830,9 @@ public:
       return mozilla::LAYER_INACTIVE;
     }
     virtual bool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) MOZ_OVERRIDE;
+    virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE {
+      return false;
+    }
     NS_DISPLAY_DECL_NAME("BlendContainer", TYPE_BLEND_CONTAINER)
 
 private:
@@ -2884,6 +2892,9 @@ public:
     // Don't allow merging, each sublist must have its own layer
     return false;
   }
+  virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE {
+    return false;
+  }
   uint32_t GetFlags() { return mFlags; }
   NS_DISPLAY_DECL_NAME("OwnLayer", TYPE_OWN_LAYER)
 protected:
@@ -3171,6 +3182,9 @@ public:
                                    const nsRect& aAllowVisibleRegionExpansion) MOZ_OVERRIDE;  
   virtual bool TryMerge(nsDisplayListBuilder* aBuilder,
                         nsDisplayItem* aItem) MOZ_OVERRIDE;
+  virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE {
+    return false;
+  }
   NS_DISPLAY_DECL_NAME("SVGEffects", TYPE_SVG_EFFECTS)
 
   virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
diff --git a/layout/forms/nsSelectsAreaFrame.cpp b/layout/forms/nsSelectsAreaFrame.cpp
index 14f33a94a11..006ba401c48 100644
--- a/layout/forms/nsSelectsAreaFrame.cpp
+++ b/layout/forms/nsSelectsAreaFrame.cpp
@@ -37,6 +37,9 @@ public:
     : nsDisplayWrapList(aBuilder, aFrame, aList) {}
   virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
                        HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames);
+  virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE {
+    return false;
+  }
   NS_DISPLAY_DECL_NAME("OptionEventGrabber", TYPE_OPTION_EVENT_GRABBER)
 };
 
diff --git a/layout/xul/nsBoxFrame.cpp b/layout/xul/nsBoxFrame.cpp
index 3c8d47ad58d..21ad008bef4 100644
--- a/layout/xul/nsBoxFrame.cpp
+++ b/layout/xul/nsBoxFrame.cpp
@@ -2012,6 +2012,9 @@ public:
   virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
                        HitTestState* aState,
                        nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
+  virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) MOZ_OVERRIDE {
+    return false;
+  }
   NS_DISPLAY_DECL_NAME("XULEventRedirector", TYPE_XUL_EVENT_REDIRECTOR)
 private:
   nsIFrame* mTargetFrame;