Bug 1400618 part 6 - Remove the workaround for the broken IsPrimaryFrame() in nsFrame::DestroyFrom since it now works also for NAC frames. r=bz

MozReview-Commit-ID: 1DFyWZBpzwP

layout/generic/nsFrame.cpp

@@ -763,14 +763,7 @@ nsFrame::DestroyFrom(nsIFrame* aDestructRoot, PostDestroyData& aPostDestroyData)
     }
   }
 
-  // XXXneerja All instances of 'mContent->GetPrimaryFrame() == this' have been
-  // replaced with IsPrimaryFrame() except for this one.  The reason is that
-  // for native anonymous content our subclass Destroy method has already
-  // called UnbindFromTree so nsINode::mSubtreeRoot might be in use here and
-  // we don't want to call mContent->SetPrimaryFrame(nullptr) in that case.
-  // (bug 1400618 will fix that order)
-  bool isPrimaryFrame = (mContent && mContent->GetPrimaryFrame() == this);
-  if (isPrimaryFrame) {
+  if (IsPrimaryFrame()) {
     // This needs to happen before we clear our Properties() table.
     ActiveLayerTracker::TransferActivityToContent(this, mContent);
 
@@ -825,7 +818,7 @@ nsFrame::DestroyFrom(nsIFrame* aDestructRoot, PostDestroyData& aPostDestroyData)
   }
 
   // Make sure that our deleted frame can't be returned from GetPrimaryFrame()
-  if (isPrimaryFrame) {
+  if (IsPrimaryFrame()) {
     mContent->SetPrimaryFrame(nullptr);
 
     // Pass the root of a generated content subtree (e.g. ::after/::before) to