Make NGInlineItemsBuilder construct whitespace-collapsed offset mapping

third_party/WebKit/Source/core/layout/BUILD.gn

 # 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.
 
 import("//third_party/WebKit/Source/core/core.gni")
 
 blink_core_sources("layout") {
   split_count = 5
 
   sources = [
@@ skipping 305 matching lines @@
     "line/LineBreaker.h",
     "line/LineInfo.h",
     "line/LineLayoutState.h",
     "line/LineWidth.cpp",
     "line/LineWidth.h",
     "line/RootInlineBox.cpp",
     "line/RootInlineBox.h",
     "line/TrailingObjects.cpp",
     "line/TrailingObjects.h",
     "line/WordMeasurement.h",
+    "ng/api/ng_offset_mapping_builder.cc",
+    "ng/api/ng_offset_mapping_builder.h",
     "ng/geometry/ng_border_edges.cc",
     "ng/geometry/ng_border_edges.h",
     "ng/geometry/ng_box_strut.cc",
     "ng/geometry/ng_box_strut.h",
     "ng/geometry/ng_edge.h",
     "ng/geometry/ng_logical_offset.cc",
     "ng/geometry/ng_logical_offset.h",
     "ng/geometry/ng_logical_rect.cc",
     "ng/geometry/ng_logical_rect.h",
     "ng/geometry/ng_logical_size.cc",
@@ skipping 146 matching lines @@
       "LayoutThemeAndroid.h",
       "WebFontRenderingAndroid.cpp",
     ]
   }
 
   configs += [
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 }