[FlexNG] Fix devtools DCHECK.

Devtools was crashing using FlexNG as various sizes were going below zero. This was occurring as we were subtracting scrollbars from the min/max sizes, and this patch removes this logic. Bug: 845235 Change-Id: I3abb0594a94e3f23953bcab5f1dd0638468b063f Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2012161Reviewed-by: David Grogan <dgrogan@chromium.org> Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org> Cr-Commit-Position: refs/heads/master@{#733700}

[FlexNG] Fix devtools DCHECK.
Devtools was crashing using FlexNG as various sizes were going below zero. This was occurring as we were subtracting scrollbars from the min/max sizes, and this patch removes this logic. Bug: 845235 Change-Id: I3abb0594a94e3f23953bcab5f1dd0638468b063f Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2012161Reviewed-by: David Grogan <dgrogan@chromium.org> Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org> Cr-Commit-Position: refs/heads/master@{#733700}
e29a6ac8 · Ian Kilpatrick · Commit Bot · 1839ca56 · e29a6ac8 · e29a6ac8
Commit e29a6ac8 authored Jan 21, 2020 by Ian Kilpatrick Committed by Commit Bot Jan 21, 2020
2 changed files
--- a/third_party/blink/renderer/core/layout/ng/ng_flex_layout_algorithm.cc
+++ b/third_party/blink/renderer/core/layout/ng/ng_flex_layout_algorithm.cc
@@ -356,16 +356,10 @@ void NGFlexLayoutAlgorithm::ConstructAndAppendFlexItems() {
    NGBoxStrut border_padding_in_child_writing_mode =
        ComputeBorders(flex_basis_space, child) +
        ComputePadding(flex_basis_space, child_style);
-    NGBoxStrut border_scrollbar_padding_in_child_writing_mode =
-        border_padding_in_child_writing_mode +
-        ComputeScrollbars(flex_basis_space, child);

    NGPhysicalBoxStrut physical_border_padding(
        border_padding_in_child_writing_mode.ConvertToPhysical(
            child_style.GetWritingMode(), child_style.Direction()));
-    NGPhysicalBoxStrut physical_border_scrollbar_padding(
-        border_scrollbar_padding_in_child_writing_mode.ConvertToPhysical(
-            child_style.GetWritingMode(), child_style.Direction()));

    LayoutUnit main_axis_border_padding =
        is_horizontal_flow_ ? physical_border_padding.HorizontalSum()
@@ -373,9 +367,6 @@ void NGFlexLayoutAlgorithm::ConstructAndAppendFlexItems() {
    LayoutUnit cross_axis_border_padding =
        is_horizontal_flow_ ? physical_border_padding.VerticalSum()
                            : physical_border_padding.HorizontalSum();
-    LayoutUnit main_axis_border_scrollbar_padding =
-        is_horizontal_flow_ ? physical_border_scrollbar_padding.HorizontalSum()
-                            : physical_border_scrollbar_padding.VerticalSum();

    // TODO(dgrogan): Don't layout every time, just when you need to.
    // Use ChildHasIntrinsicMainAxisSize as a guide.
@@ -558,9 +549,10 @@ void NGFlexLayoutAlgorithm::ConstructAndAppendFlexItems() {
          min, layout_result->IntrinsicBlockSize(),
          LengthResolvePhase::kLayout);
    }
-    // TODO(dgrogan): Should this include scrollbar?
-    min_max_sizes_in_main_axis_direction -= main_axis_border_scrollbar_padding;
+    min_max_sizes_in_main_axis_direction -= main_axis_border_padding;

+    // TODO(dgrogan): Should min_max_sizes_in_cross_axis_direction include
+    // cross_axis_border_padding?
    NGPhysicalBoxStrut physical_child_margins =
        ComputePhysicalMargins(flex_basis_space, child_style);
    algorithm_

--- a/third_party/blink/web_tests/external/wpt/css/css-flexbox/zero-content-size-with-scrollbar-crash.html
+++ b/third_party/blink/web_tests/external/wpt/css/css-flexbox/zero-content-size-with-scrollbar-crash.html
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.csswg.org/css-flexbox-1/">
+<meta name="assert" content="This test passes if the renderer does not crash."/>
+<div style="display: flex;">
+  <div style="max-width: 0px; overflow: scroll;"></div>
+</div>