Revert "[PE] Don't ignore clip change not across transform boundary"

This reverts commit 3b36628.

Reason for revert: Suspect this broke the build.

Unexpected Failures:
* compositing/geometry/repaint-foreground-layer.html
* compositing/gestures/gesture-tapHighlight-1-iframe-composited-scrolled-clipped.html
* compositing/gestures/gesture-tapHighlight-1-iframe-composited-scrolled-late-noncomposite.html
* compositing/gestures/gesture-tapHighlight-1-iframe-composited-scrolled.html
* compositing/gestures/gesture-tapHighlight-1-iframe-composited.html
* compositing/gestures/gesture-tapHighlight-1-overflow-div-composited-scroll-clip.html
* compositing/gestures/gesture-tapHighlight-1-overflow-div-composited-scrolled.html
* compositing/gestures/gesture-tapHighlight-1-overflow-div-composited.html
* compositing/gestures/gesture-tapHighlight-1-overflow-div-scrolled-late-noncomposite.html
* compositing/gestures/gesture-tapHighlight-2-iframe-composited-inner.html
* compositing/gestures/gesture-tapHighlight-2-iframe-composited-outer.html
* compositing/gestures/gesture-tapHighlight-2-iframe-scrolled-inner-late-composite.html
* compositing/gestures/gesture-tapHighlight-2-overflow-div-composited-inner-scroll-inner.html
* compositing/gestures/gesture-tapHighlight-2-overflow-div-composited-inner-scroll-outer.html
* compositing/gestures/gesture-tapHighlight-2-overflow-div-composited-inner.html
* compositing/gestures/gesture-tapHighlight-2-overflow-div-composited-outer-scroll-inner.html
* compositing/gestures/gesture-tapHighlight-2-overflow-div-composited-outer-scroll-outer.html
* compositing/gestures/gesture-tapHighlight-2-overflow-div-composited-outer.html
* compositing/gestures/gesture-tapHighlight-img-and-text-2.html
* compositing/gestures/gesture-tapHighlight-img-and-text.html
* compositing/gestures/gesture-tapHighlight-pixel-rotated-link.html
* compositing/gestures/gesture-tapHighlight-simple-cancel2.html
* compositing/gestures/gesture-tapHighlight-simple-longPress.html
* compositing/gestures/gesture-tapHighlight-simple-margin.html
* compositing/gestures/gesture-tapHighlight-simple-multi-line.html
* compositing/gestures/gesture-tapHighlight-simple-nested.html
* compositing/gestures/gesture-tapHighlight-simple-scaledX.html
* compositing/gestures/gesture-tapHighlight-simple-scaledY.html
* compositing/gestures/gesture-tapHighlight-simple-window-scroll.html
* compositing/gestures/gesture-tapHighlight-simple.html

Original change's description:
> [PE] Don't ignore clip change not across transform boundary
> 
> If the clip change is caused by the object having transform, we should
> not ignore the clip change because it actually affects descendants.
> 
> Bug: 790560
> Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
> Change-Id: Ifc05835e406eb265717128129c8095f3e52bb864
> Reviewed-on: https://chromium-review.googlesource.com/822919
> Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
> Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#523653}

TBR=wangxianzhu@chromium.org,trchen@chromium.org,chrishtr@chromium.org

Change-Id: Id760d5784db00715f5f16cd0eeed0cb4e2812688
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 790560
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Reviewed-on: https://chromium-review.googlesource.com/822138
Reviewed-by: Victor Miura <vmiura@chromium.org>
Commit-Queue: Victor Miura <vmiura@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523695}

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

@@ -156,6 +156,10 @@ void PrePaintTreeWalk::InvalidatePaintLayerOptimizationsIfNeeded(
 
   PaintLayer& paint_layer = *ToLayoutBoxModelObject(object).Layer();
 
+  // Ignore clips across transform boundaries.
+  if (object.StyleRef().HasTransform())
+    context.tree_builder_context->clip_changed = false;
+
   if (!context.tree_builder_context->clip_changed)
     return;
 
@@ -227,11 +231,6 @@ void PrePaintTreeWalk::Walk(const LayoutObject& object,
 
   PrePaintTreeWalkContext context(parent_context,
                                   needs_tree_builder_context_update);
-
-  // Ignore clip changes from ancestor across transform boundaries.
-  if (object.StyleRef().HasTransform())
-    context.tree_builder_context->clip_changed = false;
-
   WalkInternal(object, context);
 
   for (const LayoutObject* child = object.SlowFirstChild(); child;