Provide adjusted block-end border/padding to FinishFragmentation().

Don't provide the entire strut, since it was used incorrectly anyway.

FinishFragmentation() sometimes calls IsNodeFullyGrown(), and used to
pass the border_padding strut that was passed to it. This was wrong for
fieldsets, because, internally, fieldset padding isn't part of the
fieldset, but rather the anonymous wrapper child block. To fix this, get
the actual border/padding from the fragment builder, which is what
IsNodeFullyGrown() needs to use when calculating a block-size.

This isn't fixing any known issue, but I was playing with some code, and
stumbled into the DCHECK_GE() failure in IsNodeFullyGrown() when
fieldset block-size was non-auto. Example:

<fieldset style="height:100px; border:10px solid; padding:30px;">

The border-box size should be 180px. This is what would be passed as
current_total_block_size (correct). The border_padding passed would be
10px on each side (just the border, no padding - WRONG!), and the call
to ComputeBlockSizeForFragment() would only return 120px, triggering the
DCHECK.

No behavior changes intended.

Change-Id: I9782f785e2b915b8a4784c443389ba9d434ec5c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2438061Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Alison Maher <almaher@microsoft.com>
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811976}

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

@@ -2180,7 +2180,8 @@ bool NGBlockLayoutAlgorithm::FinalizeForFragmentation() {
   }
 
   return FinishFragmentation(Node(), ConstraintSpace(), BreakToken(),
-                             BorderPadding(), space_left, &container_builder_);
+                             BorderPadding().block_end, space_left,
+                             &container_builder_);
 }
 
 NGBreakStatus NGBlockLayoutAlgorithm::BreakBeforeChildIfNeeded(

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

@@ -303,7 +303,7 @@ scoped_refptr<const NGLayoutResult> NGColumnLayoutAlgorithm::Layout() {
     // In addition to establishing one, we're nested inside another
     // fragmentation context.
     FinishFragmentation(
-        Node(), ConstraintSpace(), BreakToken(), BorderPadding(),
+        Node(), ConstraintSpace(), BreakToken(), BorderPadding().block_end,
         FragmentainerSpaceAtBfcStart(ConstraintSpace()), &container_builder_);
   }
 

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

@@ -126,9 +126,9 @@ scoped_refptr<const NGLayoutResult> NGFieldsetLayoutAlgorithm::Layout() {
   container_builder_.SetIsFieldsetContainer();
 
   if (ConstraintSpace().HasBlockFragmentation()) {
-    FinishFragmentation(Node(), ConstraintSpace(), BreakToken(), borders_,
-                        FragmentainerSpaceAtBfcStart(ConstraintSpace()),
-                        &container_builder_);
+    FinishFragmentation(
+        Node(), ConstraintSpace(), BreakToken(), borders_.block_end,
+        FragmentainerSpaceAtBfcStart(ConstraintSpace()), &container_builder_);
   }
 
   NGOutOfFlowLayoutPart(Node(), ConstraintSpace(), &container_builder_).Run();

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

@@ -232,7 +232,7 @@ bool IsNodeFullyGrown(NGBlockNode node,
 bool FinishFragmentation(NGBlockNode node,
                          const NGConstraintSpace& space,
                          const NGBlockBreakToken* previous_break_token,
-                         const NGBoxStrut& border_padding,
+                         LayoutUnit trailing_border_padding,
                          LayoutUnit space_left,
                          NGBoxFragmentBuilder* builder) {
   LayoutUnit previously_consumed_block_size;
@@ -280,7 +280,7 @@ bool FinishFragmentation(NGBlockNode node,
     // haven't already consumed (100px - 20px = 80px) over two columns. We get
     // two fragments for #container after the spanner, each 40px tall.
     final_block_size = std::min(final_block_size, intrinsic_block_size) -
-                       border_padding.block_end;
+                       trailing_border_padding;
   } else if (space_left != kIndefiniteSize && desired_block_size > space_left) {
     // We're taller than what we have room for. We don't want to use more than
     // |space_left|, but if the intrinsic block-size is larger than that, it
@@ -294,12 +294,12 @@ bool FinishFragmentation(NGBlockNode node,
     //
     // There is a last-resort breakpoint before trailing border and padding, so
     // first check if we can break there and still make progress.
-    DCHECK_GE(intrinsic_block_size, border_padding.block_end);
-    DCHECK_GE(desired_block_size, border_padding.block_end);
+    DCHECK_GE(intrinsic_block_size, trailing_border_padding);
+    DCHECK_GE(desired_block_size, trailing_border_padding);
 
     LayoutUnit subtractable_border_padding;
-    if (desired_block_size > border_padding.block_end)
-      subtractable_border_padding = border_padding.block_end;
+    if (desired_block_size > trailing_border_padding)
+      subtractable_border_padding = trailing_border_padding;
 
     final_block_size =
         std::min(desired_block_size - subtractable_border_padding,
@@ -381,7 +381,7 @@ bool FinishFragmentation(NGBlockNode node,
       // more), we're only at the end if no in-flow content inside broke.
       if (!builder->HasInflowChildBreakInside() ||
           IsNodeFullyGrown(node, space, fragments_total_block_size,
-                           border_padding,
+                           builder->BorderPadding(),
                            builder->InitialBorderBoxSize().inline_size))
         builder->SetIsAtBlockEnd();
 

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

@@ -149,7 +149,7 @@ bool IsNodeFullyGrown(NGBlockNode,
 bool FinishFragmentation(NGBlockNode node,
                          const NGConstraintSpace&,
                          const NGBlockBreakToken* previous_break_token,
-                         const NGBoxStrut& border_padding,
+                         LayoutUnit trailing_border_padding,
                          LayoutUnit space_left,
                          NGBoxFragmentBuilder*);