[LayoutNG] Avoid creating empty LineBoxData in NGLineBuilder

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

Index: third_party/WebKit/Source/core/layout/ng/ng_line_builder.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_line_builder.cc b/third_party/WebKit/Source/core/layout/ng/ng_line_builder.cc
index 95191f742924578bcfa32c7ddfae419c75a5795f..2c2a23d1d3cc9ce51c2004364225a91cec2c552c 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_line_builder.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_line_builder.cc
@@ -77,14 +77,16 @@ void NGLineBuilder::CreateLine() {
   }
   DCHECK_EQ(fragments_.size(), offsets_.size());
 
-  line_box_data_list_.grow(line_box_data_list_.size() + 1);
-  LineBoxData& line_box_data = line_box_data_list_.back();
-  line_box_data.fragment_end = fragments_.size();
-  line_box_data.inline_size = inline_offset;
-
-  max_inline_size_ = std::max(max_inline_size_, inline_offset);
-  // TODO(kojii): Implement block size when we support baseline alignment.
-  content_size_ += LayoutUnit(100);
+  if (!fragments_.isEmpty()) {
+    line_box_data_list_.grow(line_box_data_list_.size() + 1);
+    LineBoxData& line_box_data = line_box_data_list_.back();
+    line_box_data.fragment_end = fragments_.size();
+    line_box_data.inline_size = inline_offset;
+
+    max_inline_size_ = std::max(max_inline_size_, inline_offset);
+    // TODO(kojii): Implement block size when we support baseline alignment.
+    content_size_ += LayoutUnit(100);
+  }
 
   line_item_chunks_.clear();
 #if DCHECK_IS_ON()