[LayoutNG] Add CalculateChildPercentageSize utility function.

Fixes percentage sized floats which were previously not using the
correct percentage resolution size.

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: Ie57909b7f452f5d59b8dfe2f899bedf253ab90ac
Reviewed-on: https://chromium-review.googlesource.com/1205200
Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#588959}

third_party/WebKit/LayoutTests/external/wpt/css/CSS2/normal-flow/float-percentage-resolution-quirks-mode.html

+<title>In quirks mode a float should resolve its percentage height against its first ancestor with a defined height.</title>
+<link rel="help" href="https://www.w3.org/TR/CSS22/visudet.html#Computing_widths_and_margins">
+<link rel="match" href="../../reference/ref-filled-green-100px-square-only.html">
+<p style="margin-top: 1em;">Test passes if there is a filled green square.</p>
+<div style="width:100px; height:100px; background:red;">
+  <div>
+    <div></div>
+    <div style="float:left; width:100%; height:100%; background:green;"></div>
+  </div>
+</div>

third_party/blink/renderer/core/layout/ng/ng_block_layout_algorithm.cc

@@ -364,23 +364,10 @@ scoped_refptr<NGLayoutResult> NGBlockLayoutAlgorithm::Layout() {
   NGLogicalSize border_box_size = CalculateBorderBoxSize(
       ConstraintSpace(), Node(), CalculateDefaultBlockSize(), border_padding_);
 
-  // Our calculated block-axis size may be indefinite at this point.
-  // If so, just leave the size as NGSizeIndefinite instead of subtracting
-  // borders and padding.
-  NGLogicalSize adjusted_size =
+  child_available_size_ =
       CalculateContentBoxSize(border_box_size, border_scrollbar_padding_);
-
-  child_available_size_ = adjusted_size;
-
-  // Anonymous constraint spaces are auto-sized. Don't let that affect
-  // block-axis percentage resolution.
-  if (ConstraintSpace().IsAnonymous() || Node().IsAnonymousBlock())
-    child_percentage_size_ = ConstraintSpace().PercentageResolutionSize();
-  else
-    child_percentage_size_ = adjusted_size;
-  if (ConstraintSpace().IsFixedSizeBlock() &&
-      !ConstraintSpace().FixedSizeBlockIsDefinite())
-    child_percentage_size_.block_size = NGSizeIndefinite;
+  child_percentage_size_ = CalculateChildPercentageSize(
+      ConstraintSpace(), Node(), child_available_size_);
 
   container_builder_.SetInlineSize(border_box_size.inline_size);
   container_builder_.SetBfcLineOffset(
@@ -1815,19 +1802,8 @@ NGBlockLayoutAlgorithm::CreateConstraintSpaceForChild(
     const base::Optional<LayoutUnit> floats_bfc_block_offset) {
   NGConstraintSpaceBuilder space_builder(ConstraintSpace());
 
-  NGLogicalSize available_size(child_available_size);
-  NGLogicalSize percentage_size(child_percentage_size_);
-  if (percentage_size.block_size == NGSizeIndefinite &&
-      Node().GetDocument().InQuirksMode()) {
-    // Implement percentage height calculation quirk
-    // https://quirks.spec.whatwg.org/#the-percentage-height-calculation-quirk
-    if (!Style().IsDisplayTableType() && !Style().HasOutOfFlowPosition()) {
-      percentage_size.block_size =
-          constraint_space_.PercentageResolutionSize().block_size;
-    }
-  }
-  space_builder.SetAvailableSize(available_size)
-      .SetPercentageResolutionSize(percentage_size);
+  space_builder.SetAvailableSize(child_available_size)
+      .SetPercentageResolutionSize(child_percentage_size_);
 
   if (NGBaseline::ShouldPropagateBaselines(child))
     space_builder.AddBaselineRequests(ConstraintSpace().BaselineRequests());

third_party/blink/renderer/core/layout/ng/ng_length_utils.cc

@@ -939,4 +939,30 @@ NGLogicalSize CalculateContentBoxSize(
   return size;
 }
 
+NGLogicalSize CalculateChildPercentageSize(
+    const NGConstraintSpace& space,
+    const NGBlockNode node,
+    const NGLogicalSize& child_available_size) {
+  // Anonymous block or spaces should pass the percent size straight through.
+  if (space.IsAnonymous() || node.IsAnonymousBlock())
+    return space.PercentageResolutionSize();
+
+  NGLogicalSize child_percentage_size = child_available_size;
+
+  if (space.IsFixedSizeBlock() && !space.FixedSizeBlockIsDefinite())
+    child_percentage_size.block_size = NGSizeIndefinite;
+
+  // In quirks mode the percentage resolution height is passed from parent to
+  // child.
+  // https://quirks.spec.whatwg.org/#the-percentage-height-calculation-quirk
+  if (child_percentage_size.block_size == NGSizeIndefinite &&
+      node.GetDocument().InQuirksMode() && !node.Style().IsDisplayTableType() &&
+      !node.Style().HasOutOfFlowPosition()) {
+    child_percentage_size.block_size =
+        space.PercentageResolutionSize().block_size;
+  }
+
+  return child_percentage_size;
+}
+
 }  // namespace blink

third_party/blink/renderer/core/layout/ng/ng_length_utils.h

@@ -249,6 +249,12 @@ NGLogicalSize CalculateContentBoxSize(
     const NGLogicalSize border_box_size,
     const NGBoxStrut& border_scrollbar_padding);
 
+// Calculates the percentage resolution size children of node should use.
+NGLogicalSize CalculateChildPercentageSize(
+    const NGConstraintSpace&,
+    const NGBlockNode node,
+    const NGLogicalSize& child_available_size);
+
 }  // namespace blink
 
 #endif  // NGLengthUtils_h