Bug 703241. Part 2: Stop the 'scroll top of line into view' behavior when ancestors in the line are transformed or positioned. Allow that behavior for any kind of line-participant ancestor. r=mats

--HG--
extra : rebase_source : bcbe05a09fe9f5423bb09697f8be3c6ce0c44f46

layout/base/nsPresShell.cpp

@@ -3005,19 +3005,18 @@ AccumulateFrameBounds(nsIFrame* aContainerFrame,
   // layout model) or aUseWholeLineHeightForInlines is set, we need to
   // change the top of the bounds to include the whole line.
   if (frameBounds.height == 0 || aUseWholeLineHeightForInlines) {
-    nsIAtom* frameType = NULL;
     nsIFrame *prevFrame = aFrame;
     nsIFrame *f = aFrame;
 
-    while (f &&
-           (frameType = f->GetType()) == nsGkAtoms::inlineFrame) {
+    while (f && f->IsFrameOfType(nsIFrame::eLineParticipant) &&
+           !f->IsTransformed() && !f->IsPositioned()) {
       prevFrame = f;
       f = prevFrame->GetParent();
     }
 
     if (f != aFrame &&
         f &&
-        frameType == nsGkAtoms::blockFrame) {
+        f->GetType() == nsGkAtoms::blockFrame) {
       // find the line containing aFrame and increase the top of |offset|.
       if (f != aPrevBlock) {
         aLines = f->GetLineIterator();