[LayoutNG] Support objects that are opaque to whitespace collapsing

third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder_test.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/inline/ng_inline_items_builder.h"
 
 #include "core/layout/LayoutInline.h"
 #include "core/layout/ng/inline/ng_inline_node.h"
 #include "core/style/ComputedStyle.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 202 matching lines @@
   EXPECT_EQ(String(u"A \u4E00"), TestAppend(u"A\n\u4E00"))
       << "Newline is not removed when before is Narrow.";
 
   EXPECT_EQ(String(u"\u4E00\u4E00"), TestAppend(u"\u4E00\n", u"\u4E00"))
       << "Newline at the end of elements is removed when both sides are Wide.";
   EXPECT_EQ(String(u"\u4E00\u4E00"), TestAppend(u"\u4E00", u"\n\u4E00"))
       << "Newline at the beginning of elements is removed "
          "when both sides are Wide.";
 }
 
+TEST_F(NGInlineItemsBuilderTest, OpaqueToSpaceCollapsing) {
+  NGInlineItemsBuilder builder(&items_);
+  builder.Append("Hello ", style_.Get());
+  builder.AppendOpaque(NGInlineItem::kBidiControl,
+                       kFirstStrongIsolateCharacter);
+  builder.Append(" ", style_.Get());
+  builder.AppendOpaque(NGInlineItem::kBidiControl,
+                       kFirstStrongIsolateCharacter);
+  builder.Append(" World", style_.Get());
+  EXPECT_EQ(String(u"Hello \u2068\u2068World"), builder.ToString());
+}
+
 TEST_F(NGInlineItemsBuilderTest, CollapseAroundReplacedElement) {
   NGInlineItemsBuilder builder(&items_);
   builder.Append("Hello ", style_.Get());
   builder.Append(NGInlineItem::kAtomicInline, kObjectReplacementCharacter);
   builder.Append(" World", style_.Get());
   EXPECT_EQ(String(u"Hello \uFFFC World"), builder.ToString());
 }
 
 TEST_F(NGInlineItemsBuilderTest, CollapseNewlineAfterObject) {
   NGInlineItemsBuilder builder(&items_);
@@ skipping 105 matching lines @@
                    u"\u2068\u202E"
                    u"\u05E2\u05D1\u05E8\u05D9\u05EA"
                    u"\u202C\u2069"
                    u" World"),
             builder.ToString());
 }
 
 }  // namespace
 
 }  // namespace blink