[layoutng] Add an NGFragmentBuilder

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

+// Copyright 2016 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/ng_fragment_builder.h"
+
+namespace blink {
+
+NGFragmentBuilder::NGFragmentBuilder(NGFragmentBase::NGFragmentType type)
+    : type_(type),
+      writing_mode_(HorizontalTopBottom),
+      direction_(LeftToRight) {}
+
+NGFragmentBuilder& NGFragmentBuilder::SetWritingMode(
+    NGWritingMode writing_mode) {
+  writing_mode_ = writing_mode;
+  return *this;
+}
+
+NGFragmentBuilder& NGFragmentBuilder::SetDirection(NGDirection direction) {
+  direction_ = direction;
+  return *this;
+}
+
+NGFragmentBuilder& NGFragmentBuilder::SetInlineSize(LayoutUnit size) {
+  size_.inlineSize = size;
+  return *this;
+}
+
+NGFragmentBuilder& NGFragmentBuilder::SetBlockSize(LayoutUnit size) {
+  size_.blockSize = size;
+  return *this;
+}
+
+NGFragmentBuilder& NGFragmentBuilder::SetInlineOverflow(LayoutUnit size) {
+  overflow_.inlineSize = size;
+  return *this;
+}
+
+NGFragmentBuilder& NGFragmentBuilder::SetBlockOverflow(LayoutUnit size) {
+  overflow_.blockSize = size;
+  return *this;
+}
+
+NGFragmentBuilder& NGFragmentBuilder::AddChild(const NGFragment* child) {
+  DCHECK_EQ(type_, NGFragmentBase::FragmentBox)
+      << "Only box fragments can have children";
+  children_.append(child);
+  return *this;
+}
+
+NGFragment* NGFragmentBuilder::ToFragment() {
+  // TODO(layout-ng): Support text fragments
+  DCHECK_EQ(type_, NGFragmentBase::FragmentBox);
+  NGFragment* fragment =
+      new NGFragment(size_, overflow_, writing_mode_, direction_, children_);
+  return fragment;
+}
+
+}  // namespace blink