[LayoutNG] Fix abspos crash caused by edge conditions

Bug: 740993
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: Iebb2dea88b6e111893de79e86854d92dcd3932f8
Reviewed-on: https://chromium-review.googlesource.com/1123114Reviewed-by: Koji Ishii <kojii@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Aleks Totic <atotic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572054}

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

@@ -302,7 +302,6 @@ crbug.com/591099 external/wpt/html/rendering/non-replaced-elements/the-fieldset-
 crbug.com/591099 external/wpt/html/rendering/replaced-elements/svg-embedded-sizing/svg-in-img-auto.html [ Failure ]
 crbug.com/591099 external/wpt/html/rendering/replaced-elements/svg-embedded-sizing/svg-in-img-percentage.html [ Failure ]
 crbug.com/591099 external/wpt/html/rendering/replaced-elements/svg-inline-sizing/svg-inline.html [ Failure ]
-crbug.com/591099 external/wpt/html/semantics/interactive-elements/the-dialog-element/centering.html [ Crash ]
 crbug.com/591099 external/wpt/payment-handler/can-make-payment-event-constructor.https.worker.html [ Pass ]
 crbug.com/591099 external/wpt/payment-request/payment-allowed-by-feature-policy.https.sub.html [ Pass ]
 crbug.com/591099 external/wpt/payment-request/payment-disabled-by-feature-policy.https.sub.html [ Pass ]

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

@@ -40,11 +40,14 @@ NGOutOfFlowLayoutPart::NGOutOfFlowLayoutPart(
 
   default_containing_block_.style = &container_style;
   default_containing_block_.content_size = container_builder_->Size();
-  default_containing_block_.content_size.inline_size -=
-      borders_and_scrollers.InlineSum();
-  default_containing_block_.content_size.block_size -=
-      borders_and_scrollers.BlockSum();
-
+  default_containing_block_.content_size.inline_size =
+      std::max(default_containing_block_.content_size.inline_size -
+                   borders_and_scrollers.InlineSum(),
+               LayoutUnit());
+  default_containing_block_.content_size.block_size =
+      std::max(default_containing_block_.content_size.block_size -
+                   borders_and_scrollers.BlockSum(),
+               LayoutUnit());
   default_containing_block_.content_offset = NGLogicalOffset{
       borders_and_scrollers.inline_start, borders_and_scrollers.block_start};
   default_containing_block_.content_physical_offset =