Fix touch event flag may not be updated correctly by transform which causes no layout

third_party/WebKit/Source/core/paint/PaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 400 matching lines @@
     clipper().clearClipRectsIncludingDescendants(AbsoluteClipRects);
   }
 
   updateTransformationMatrix();
 
   if (had3DTransform != has3DTransform())
     markAncestorChainForDescendantDependentFlagsUpdate();
 
   if (FrameView* frameView = layoutObject()->document().view())
     frameView->setNeedsUpdateWidgetGeometries();
+
+  if (ScrollingCoordinator* scrollingCoordinator =
+          layoutObject()->frame()->page()->scrollingCoordinator())
+    scrollingCoordinator->checkTransformChangedDueToTouchEvent(this);

[majidvp, 2017/01/04 16:48:51]

Is t really enough to notify ScrollingCoordinator when a PaintLayer transform
changes?

What about cases where a layout object transform is changed but it does not have
a layer. I think
in those cases we still compute touch rects but in enclosing layer's space. I
imagine those rects
need to be updated, no?

[yigu, 2017/01/05 14:05:43]

As we discussed, this part of logic has been moved to layoutBox.

 }
 
 static PaintLayer* enclosingLayerForContainingBlock(PaintLayer* layer) {
   if (LayoutObject* containingBlock = layer->layoutObject()->containingBlock())
     return containingBlock->enclosingLayer();
   return 0;
 }
 
 static const PaintLayer* enclosingLayerForContainingBlock(
     const PaintLayer* layer) {
@@ skipping 2808 matching lines @@
 }
 
 void showLayerTree(const blink::LayoutObject* layoutObject) {
   if (!layoutObject) {
     LOG(INFO) << "Cannot showLayerTree. Root is (nil)";
     return;
   }
   showLayerTree(layoutObject->enclosingLayer());
 }
 #endif