Add a basic support of text-align:right property to NGInlineLayoutAlgorithm.

third_party/WebKit/Source/core/layout/ng/inline/ng_line_box_fragment_builder.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_line_box_fragment_builder.h"
 
 #include "core/layout/ng/geometry/ng_logical_size.h"
 #include "core/layout/ng/inline/ng_inline_break_token.h"
 #include "core/layout/ng/inline/ng_inline_node.h"
 #include "core/layout/ng/inline/ng_physical_line_box_fragment.h"
@@ skipping 24 matching lines @@
   offsets_.push_back(child_offset);
 
   return *this;
 }
 
 void NGLineBoxFragmentBuilder::MoveChildrenInBlockDirection(LayoutUnit delta) {
   for (auto& offset : offsets_)
     offset.block_offset += delta;
 }
 
+void NGLineBoxFragmentBuilder::MoveChildrenInInlineDirection(
+    LayoutUnit available_inline_size) {
+  NGWritingMode writing_mode(
+      FromPlatformWritingMode(node_->Style().GetWritingMode()));
+  LayoutUnit base_inline_offset = available_inline_size - inline_size_;

[kojii, 2017/05/22 03:27:03]

Can't we add delta instead? The position may not be the sum of sizes.

Were there cases where doing so doesn't work well? If so, can you leave
comments, because I'll need to change this to adding delta sometime soon to
support inline margins.

+  LayoutUnit child_inline_size;
+  for (size_t i = 0; i < children_.size(); ++i) {
+    offsets_[i].inline_offset = base_inline_offset + child_inline_size;
+    NGPhysicalFragment* child = children_[i].Get();
+    child_inline_size +=
+        child->Size().ConvertToLogical(writing_mode).inline_size;
+  }
+}
+
 void NGLineBoxFragmentBuilder::MoveChildrenInBlockDirection(LayoutUnit delta,
                                                             unsigned start,
                                                             unsigned end) {
   for (unsigned index = start; index < end; index++)
     offsets_[index].block_offset += delta;
 }
 
 void NGLineBoxFragmentBuilder::SetMetrics(const NGLineHeightMetrics& metrics) {
   metrics_ = metrics;
 }
@@ skipping 19 matching lines @@
         writing_mode, direction_, physical_size, child->Size()));
   }
 
   return AdoptRef(new NGPhysicalLineBoxFragment(
       physical_size, children_, metrics_,
       break_token_ ? std::move(break_token_)
                    : NGInlineBreakToken::Create(node_)));
 }
 
 }  // namespace blink