[LayoutNG] Fix DCHECK by early return if no results

Bug: 740993
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: I38981d061a410067921984516eb9f1894762e8ca
Reviewed-on: https://chromium-review.googlesource.com/940563Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Aleks Totic <atotic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539892}

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

@@ -1247,10 +1247,7 @@ crbug.com/591099 external/wpt/css/css-tables/fixup-dynamic-anonymous-inline-tabl
 crbug.com/591099 external/wpt/css/css-tables/fixup-dynamic-anonymous-table-001.html [ Pass ]
 crbug.com/591099 external/wpt/css/css-tables/floats/floats-wrap-bfc-006c.xht [ Pass ]
 crbug.com/591099 external/wpt/css/css-tables/height-distribution/percentage-sizing-of-table-cell-children.html [ Failure ]
-crbug.com/591099 external/wpt/css/css-tables/html5-table-formatting-fixed-layout-1.html [ Crash ]
 crbug.com/591099 external/wpt/css/css-tables/table-model-fixup-2.html [ Failure Pass ]
-crbug.com/591099 external/wpt/css/css-tables/visibility-collapse-rowcol-001.html [ Crash ]
-crbug.com/591099 external/wpt/css/css-tables/visibility-collapse-rowspan-crash.html [ Crash ]
 crbug.com/591099 external/wpt/css/css-text-decor/text-emphasis-color-001.xht [ Failure ]
 crbug.com/591099 external/wpt/css/css-text-decor/text-emphasis-position-above-left-001.xht [ Failure ]
 crbug.com/591099 external/wpt/css/css-text-decor/text-emphasis-position-above-left-002.xht [ Failure ]
@@ -1961,7 +1958,7 @@ crbug.com/591099 external/wpt/html/the-xhtml-syntax/parsing-xhtml-documents/xhtm
 crbug.com/591099 external/wpt/html/the-xhtml-syntax/parsing-xhtml-documents/xhtml-mathml-dtd-entity-7.htm [ Pass Timeout ]
 crbug.com/591099 external/wpt/html/the-xhtml-syntax/parsing-xhtml-documents/xhtml-mathml-dtd-entity-8.htm [ Pass Timeout ]
 crbug.com/591099 external/wpt/http/basic-auth-cache-test.html [ Timeout ]
-crbug.com/591099 external/wpt/innerText/getter.html [ Crash ]
+crbug.com/591099 external/wpt/innerText/getter.html [ Failure ]
 crbug.com/591099 external/wpt/intersection-observer/remove-element.html [ Failure ]
 crbug.com/714962 external/wpt/intersection-observer/root-margin.html [ Failure ]
 crbug.com/591099 external/wpt/intersection-observer/same-document-root.html [ Failure ]
@@ -5393,7 +5390,7 @@ crbug.com/591099 tables/mozilla_expected_failures/marvin/table_overflow_caption_
 crbug.com/591099 tables/mozilla_expected_failures/marvin/table_overflow_caption_top.html [ Failure ]
 crbug.com/714962 tables/mozilla_expected_failures/marvin/tables_cellspacing_pct.html [ Failure ]
 crbug.com/714962 tables/mozilla_expected_failures/marvin/x_colgroup_width_px.xml [ Failure ]
-crbug.com/591099 tables/mozilla_expected_failures/other/test4.html [ Crash ]
+crbug.com/591099 tables/mozilla_expected_failures/other/test4.html [ Failure ]
 crbug.com/714962 touchadjustment/context-menu-select-text.html [ Failure ]
 crbug.com/714962 touchadjustment/context-menu-text-subtargets.html [ Failure ]
 crbug.com/714962 touchadjustment/touch-links-longpress.html [ Failure ]

third_party/WebKit/Source/core/layout/ng/ng_container_fragment_builder.cc

@@ -167,6 +167,9 @@ void NGContainerFragmentBuilder::GetAndClearOutOfFlowDescendantCandidates(
     const LayoutObject* current_container) {
   DCHECK(descendant_candidates->IsEmpty());
 
+  if (oof_positioned_candidates_.size() == 0)
+    return;
+
   descendant_candidates->ReserveCapacity(oof_positioned_candidates_.size());
 
   DCHECK_GE(inline_size_, LayoutUnit());