Simpler fix for bugs 307809 and 314502. b=352449 r+sr=bzbarsky

layout/xul/base/src/grid/nsGrid.cpp

@@ -1466,7 +1466,7 @@ nsGrid::GetScrolledBox(nsIBox* aChild)
       if (scrollFrame) {
          nsIFrame* scrolledFrame = scrollFrame->GetScrolledFrame();
          NS_ASSERTION(scrolledFrame,"Error no scroll frame!!");
-         return scrolledFrame->IsBoxFrame() ? scrolledFrame : nsnull;
+         return scrolledFrame;
       }
 
       return aChild;

layout/xul/base/src/grid/nsGridRowGroupLayout.cpp

@@ -206,11 +206,7 @@ nsGridRowGroupLayout::DirtyRows(nsIBox* aBox, nsBoxLayoutState& aState)
 
       // walk into other monuments
       nsCOMPtr<nsIBoxLayout> layout;
-      // deepChild might be null if child is a scrollframe around a non-box.
+      deepChild->GetLayoutManager(getter_AddRefs(layout));
-      // But in that case there's nothing to do here, really.
-      if (deepChild) {
-        deepChild->GetLayoutManager(getter_AddRefs(layout));
-      }
       if (layout) {
         nsCOMPtr<nsIGridPart> monument( do_QueryInterface(layout) );
         if (monument) 
@@ -240,12 +236,7 @@ nsGridRowGroupLayout::CountRowsColumns(nsIBox* aBox, PRInt32& aRowCount, PRInt32
       nsIBox* deepChild = nsGrid::GetScrolledBox(child);
 
       nsCOMPtr<nsIBoxLayout> layout;
-      // deepChild might be null if child is a scrollframe around a non-box.
+      deepChild->GetLayoutManager(getter_AddRefs(layout));
-      // But in that case I guess we can count this as a single grid row.  Or
-      // something.
-      if (deepChild) {
-        deepChild->GetLayoutManager(getter_AddRefs(layout));
-      }
       if (layout) {
         nsCOMPtr<nsIGridPart> monument( do_QueryInterface(layout) );
         if (monument) {
@@ -299,11 +290,7 @@ nsGridRowGroupLayout::BuildRows(nsIBox* aBox, nsGridRow* aRows, PRInt32* aCount)
       nsIBox* deepChild = nsGrid::GetScrolledBox(child);
 
       nsCOMPtr<nsIBoxLayout> layout;
-      // deepChild might be null if child is a scrollframe around a non-box.
+      deepChild->GetLayoutManager(getter_AddRefs(layout));
-      // But in that case there's nothing special that needs doing there.
-      if (deepChild) {
-        deepChild->GetLayoutManager(getter_AddRefs(layout));
-      }
       if (layout) {
         nsCOMPtr<nsIGridPart> monument( do_QueryInterface(layout) );
         if (monument) {

layout/xul/base/src/grid/nsGridRowLayout.cpp

@@ -135,12 +135,7 @@ nsGridRowLayout::GetGrid(nsIBox* aBox, nsGrid** aList, PRInt32* aIndex, nsGridRo
      nsIBox* childBox = nsGrid::GetScrolledBox(child);
 
      nsCOMPtr<nsIBoxLayout> layout;
-     // childBox might be null if child is a scrollframe around a non-box.  But
+     childBox->GetLayoutManager(getter_AddRefs(layout));
-     // in that case I guess we can count this as a single grid row.  Or
-     // something.
-     if (childBox) {
-       childBox->GetLayoutManager(getter_AddRefs(layout));
-     }
      
      // find our requester
      nsCOMPtr<nsIGridPart> gridRow = do_QueryInterface(layout, &rv);