Bug 1269321: Part 1 - Add a way to check if the current clip has rounded corners. r=mstange

--HG--
extra : rebase_source : ebdb701125fb1ec910f09af938dcea9d95fe442f

layout/base/DisplayItemScrollClip.cpp

@@ -27,6 +27,18 @@ DisplayItemScrollClip::IsAncestor(const DisplayItemScrollClip* aAncestor,
   return false;
 }
 
+bool
+DisplayItemScrollClip::HasRoundedCorners() const
+{
+  for (const DisplayItemScrollClip* scrollClip = this;
+       scrollClip; scrollClip = scrollClip->mParent) {
+    if (scrollClip->mClip->GetRoundedRectCount() > 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
 /* static */ nsCString
 DisplayItemScrollClip::ToString(const DisplayItemScrollClip* aScrollClip)
 {

layout/base/DisplayItemScrollClip.h

@@ -90,6 +90,8 @@ public:
    */
   static nsCString ToString(const DisplayItemScrollClip* aScrollClip);
 
+  bool HasRoundedCorners() const;
+
   /**
    * The previous (outer) scroll clip, or null.
    */

layout/base/DisplayListClipState.h

@@ -269,6 +269,24 @@ public:
     Restore();
   }
 
+  bool SavedStateHasRoundedCorners()
+  {
+    const DisplayItemScrollClip* scrollClip = mSavedState.GetCurrentInnermostScrollClip();
+    if (scrollClip && scrollClip->HasRoundedCorners()) {
+      return true;
+    }
+    const DisplayItemClip* clip = mSavedState.GetClipForContainingBlockDescendants();
+    if (clip && clip->GetRoundedRectCount() > 0) {
+      return true;
+    }
+
+    clip = mSavedState.GetClipForContentDescendants();
+    if (clip && clip->GetRoundedRectCount() > 0) {
+      return true;
+    }
+    return false;
+  }
+
   void TurnClipIntoScrollClipForContentDescendants(nsDisplayListBuilder* aBuilder, nsIScrollableFrame* aScrollableFrame)
   {
     NS_ASSERTION(!mRestored, "Already restored!");