[LayoutNG] Support atomic inline+nbsp quirks

This patch adds a quirks for atomic inline+nbsp defined in
CSS Text, saying:
> for Web-compatibility, introduces a soft wrap opportunity
> between itself and any adjacent U+00A0 NO-BREAK SPACE
> character.
https://www.w3.org/TR/css-text-3/#line-break-details

This is resolved at:
https://lists.w3.org/Archives/Public/www-style/2015Mar/0187.html
> zcorpan: I checked httparchive for nbsp before/after an
> image, and there were 16k matches. About 130k pages in the
> set, so about 12% of all the pages match the query.

Bug: 993893, 1001793
Change-Id: I24c30b43f282c2005abccf5be4de68262875b87d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1792465
Commit-Queue: Emil A Eklund <eae@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#694788}

third_party/blink/renderer/core/layout/ng/inline/ng_line_breaker.cc

@@ -483,6 +483,41 @@ void NGLineBreaker::ComputeLineLocation(NGLineInfo* line_info) const {
     line_info->UpdateTextAlign();
 }
 
+// For Web-compatibility, allow break between an atomic inline and any adjacent
+// U+00A0 NO-BREAK SPACE character.
+// https://www.w3.org/TR/css-text-3/#line-break-details
+bool NGLineBreaker::IsAtomicInlineBeforeNoBreakSpace(
+    const NGInlineItemResult& item_result) const {
+  DCHECK_EQ(item_result.item->Type(), NGInlineItem::kAtomicInline);
+  const String& text = Text();
+  DCHECK_GE(text.length(), item_result.end_offset);
+  return text.length() > item_result.end_offset &&
+         text[item_result.end_offset] == kNoBreakSpaceCharacter;
+}
+
+bool NGLineBreaker::IsAtomicInlineAfterNoBreakSpace(
+    const NGInlineItemResult& item_result) const {
+  DCHECK_EQ(item_result.item->Type(), NGInlineItem::kText);
+  const String& text = Text();
+  DCHECK_GE(text.length(), item_result.end_offset);
+  if (text[item_result.end_offset - 1] != kNoBreakSpaceCharacter ||
+      text.length() <= item_result.end_offset ||
+      text[item_result.end_offset] != kObjectReplacementCharacter)
+    return false;
+  // This kObjectReplacementCharacter can be any objects, such as a floating or
+  // an OOF object. Check if it's really an atomic inline.
+  const Vector<NGInlineItem>& items = Items();
+  for (const NGInlineItem* item = std::next(item_result.item);
+       item != items.end(); ++item) {
+    DCHECK_EQ(item->StartOffset(), item_result.end_offset);
+    if (item->Type() == NGInlineItem::kAtomicInline)
+      return true;
+    if (item->EndOffset() > item_result.end_offset)
+      break;
+  }
+  return false;
+}
+
 void NGLineBreaker::HandleText(const NGInlineItem& item,
                                const ShapeResult& shape_result,
                                NGLineInfo* line_info) {
@@ -711,6 +746,9 @@ NGLineBreaker::BreakResult NGLineBreaker::BreakText(
     DCHECK_EQ(item_result->end_offset, item.EndOffset());
     item_result->can_break_after =
         break_iterator_.IsBreakable(item_result->end_offset);
+    if (!item_result->can_break_after && item.Type() == NGInlineItem::kText &&
+        IsAtomicInlineAfterNoBreakSpace(*item_result))
+      item_result->can_break_after = true;
     trailing_whitespace_ = WhitespaceState::kUnknown;
   }
   return inline_size <= available_width ? kSuccess : kOverflow;
@@ -1252,6 +1290,9 @@ bool NGLineBreaker::HandleAtomicInline(
   trailing_whitespace_ = WhitespaceState::kNone;
   position_ += item_result->inline_size;
   ComputeCanBreakAfter(item_result, auto_wrap_, break_iterator_);
+  if (!item_result->can_break_after &&
+      IsAtomicInlineBeforeNoBreakSpace(*item_result))
+    item_result->can_break_after = true;
 
   if (UNLIKELY(is_sticky_image)) {
     const auto& items = Items();

third_party/blink/renderer/core/layout/ng/inline/ng_line_breaker.h

@@ -163,6 +163,10 @@ class CORE_EXPORT NGLineBreaker {
       const NGInlineItem&,
       LayoutUnit percentage_resolution_block_size_for_min_max,
       NGLineInfo*);
+  bool IsAtomicInlineAfterNoBreakSpace(
+      const NGInlineItemResult& item_result) const;
+  bool IsAtomicInlineBeforeNoBreakSpace(
+      const NGInlineItemResult& item_result) const;
   void HandleFloat(const NGInlineItem&,
                    Vector<LayoutObject*>* out_floats_for_min_max,
                    NGLineInfo*);

third_party/blink/web_tests/TestExpectations

@@ -686,9 +686,6 @@ crbug.com/591099 external/wpt/css/css-text/boundary-shaping/boundary-shaping-009
 crbug.com/591099 external/wpt/css/css-text/hyphens/shy-styling-001.html [ Failure ]
 crbug.com/591099 external/wpt/css/css-text/line-breaking/line-breaking-018.html [ Failure ]
 crbug.com/591099 external/wpt/css/css-text/line-breaking/line-breaking-019.html [ Failure ]
-crbug.com/591099 external/wpt/css/css-text/line-breaking/line-breaking-atomic-001.html [ Failure ]
-crbug.com/591099 external/wpt/css/css-text/line-breaking/line-breaking-atomic-002.html [ Failure ]
-crbug.com/591099 external/wpt/css/css-text/line-breaking/line-breaking-replaced-001.html [ Failure ]
 crbug.com/591099 external/wpt/css/css-text/shaping/shaping-009.html [ Failure ]
 crbug.com/591099 external/wpt/css/css-text/shaping/shaping-010.html [ Failure ]
 crbug.com/591099 external/wpt/css/css-text/shaping/shaping-011.html [ Failure ]