[LayoutNG] Initial support for the 'vertical-align' property

third_party/WebKit/Source/core/layout/ng/inline/ng_inline_box_state.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/layout/ng/inline/ng_inline_box_state.h"
+
+#include "core/layout/ng/inline/ng_inline_node.h"
+#include "core/style/ComputedStyle.h"
+
+namespace blink {
+
+// Compute text metrics for a box. All text in a box share the same metrics.
+void NGInlineBoxState::ComputeTextMetrics(const NGLayoutInlineItem& item,
+                                          FontBaseline baseline_type) {
+  const ComputedStyle& style = *item.Style();
+  text_metrics = NGLineHeightMetrics(style, baseline_type);
+  text_top = -text_metrics.ascent;
+  text_metrics.AddLeading(style.ComputedLineHeightAsFixed());
+  metrics.Unite(text_metrics);
+
+  include_used_fonts = style.LineHeight().IsNegative();
+}
+
+}  // namespace blink