[LayoutNG] Stop PositionForPointInInlineFormattingContext() from entering non-line-box children

The above mentioned function is supposed to enter a line box child to
find positions in inline descendants. In some situations, the inline
formatting context have have direct non-inline child (e.g., abs-pos
float), which should be ignored.

This patch removes the existing redundant branch that enters non-line-
box children, to fix failure in
fast/shapes/shape-outside-floats/shape-outside-clip-path-selection.html.

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng;luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I834544692d6cc8d9fc4340fb55ffb1bbe53f1276
Reviewed-on: https://chromium-review.googlesource.com/1151947
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Emil A Eklund <eae@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578471}

third_party/WebKit/LayoutTests/FlagExpectations/enable-blink-features=LayoutNG

@@ -548,7 +548,6 @@ crbug.com/591099 fast/ruby/position-after.html [ Failure ]
 crbug.com/591099 fast/scrolling/content-box-smaller-than-scrollbar.html [ Failure ]
 crbug.com/591099 fast/scrolling/jquery-rtl-scroll-type.html [ Failure ]
 crbug.com/591099 fast/scrolling/scrollbar-tickmarks-hittest.html [ Failure Pass ]
-crbug.com/591099 fast/shapes/shape-outside-floats/shape-outside-clip-path-selection.html [ Failure ]
 crbug.com/591099 fast/sub-pixel/inline-block-with-padding.html [ Failure ]
 crbug.com/591099 fast/sub-pixel/repaint-subpixel-layer-in-subpixel-composited-layer.html [ Failure ]
 crbug.com/591099 fast/sub-pixel/sub-pixel-border-2.html [ Failure ]

third_party/blink/renderer/core/paint/ng/ng_paint_fragment.cc

@@ -559,18 +559,6 @@ PositionWithAffinity NGPaintFragment::PositionForPointInInlineFormattingContext(
   LayoutUnit closest_line_after_block_offset = LayoutUnit::Max();
 
   for (const auto& child : Children()) {
-    // Try to resolve if |point| falls in a non-line-box child completely.
-    if (!child->PhysicalFragment().IsLineBox()) {
-      if (point.left >= child->Offset().left &&
-          point.left <= child->Offset().left + child->Size().width &&
-          point.top >= child->Offset().top &&
-          point.top <= child->Offset().top + child->Size().height) {
-        if (auto child_position = PositionForPointInChild(*child, point))
-          return child_position.value();
-      }
-      continue;
-    }
-
     if (!child->PhysicalFragment().IsLineBox() || child->Children().IsEmpty())
       continue;
 
@@ -617,7 +605,7 @@ PositionWithAffinity NGPaintFragment::PositionForPointInInlineFormattingContext(
   // TODO(xiaochengh): Looking at only the closest lines may not be enough,
   // when we have multiple lines full of pseudo elements. Fix it.
 
-  // TODO(xiaochengh): Consider floats.
+  // TODO(xiaochengh): Consider floats. See crbug.com/758526.
 
   return PositionWithAffinity();
 }