Make TextOffsetMapping::InlineContents not to use LayoutRubyAsBlock as container

This patch changes |TextOffsetMapping::InlineContents| not to use
|LayoutRubyAsBlock| as container to avoid invalid DOM range.

In <ruby>abc<rt>XYZ</rt></ruby>, before this patch |InlineContents| use
<ruby> as container and having range start with <rt>@0 and "abc"[3] because
in layout tree, <rt> comes before "abc".

After this patch, we make |LayoutNGRubyRun| and |LayoutNGRubyBase| as
container but |LayoutNGRubyAsBlock|.

Layout tree:
      LayoutNGRubyAsBlock {RUBY} at (0,0) size 784x27
        LayoutNGRubyRun (anonymous) at (0,7) size 22x20
          LayoutNGRubyText {RT} at (0,-10) size 22x12
            LayoutText {#text} at (2,0) size 18x12
              text run at (2,0) width 18: "XYZ"
          LayoutNGRubyBase (anonymous) at (0,0) size 22x20
            LayoutText {#text} at (0,0) size 22x19
              text run at (0,0) width 22: "abc"

Bug: 1124584
Change-Id: Id4006630a87127a6af2d1a5044a07e253457f8bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2460551
Commit-Queue: Kent Tamura <tkent@chromium.org>
Auto-Submit: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815433}

third_party/blink/renderer/core/editing/text_offset_mapping.cc

@@ -40,6 +40,12 @@ bool CanBeInlineContentsContainer(const LayoutObject& layout_object) {
     return false;
   if (!block_flow->ChildrenInline() || block_flow->IsAtomicInlineLevel())
     return false;
+  if (block_flow->IsRuby()) {
+    // We should not make |LayoutRubyAsBlock| as inline contents container,
+    // because ruby base text comes after ruby text in layout tree.
+    // See ParameterizedTextOffsetMappingTest.RangeOfBlockWithRubyAsBlock
+    return false;
+  }
   if (block_flow->NonPseudoNode()) {
     // It is OK as long as |block_flow| is associated to non-pseudo |Node| even
     // if it is empty block or containing only anonymous objects.

third_party/blink/renderer/core/editing/text_offset_mapping_test.cc

@@ -196,6 +196,39 @@ TEST_P(ParameterizedTextOffsetMappingTest, RangeOfBlockWithRUBY) {
             GetRange("<ruby>abc<rt>1|23</rt></ruby>"));
 }
 
+// http://crbug.com/1124584
+TEST_P(ParameterizedTextOffsetMappingTest, RangeOfBlockWithRubyAsBlock) {
+  // We should not make <ruby> as |InlineContent| container because "XYZ" comes
+  // before "abc" but in DOM tree, order is "abc" then "XYZ".
+  // Layout tree:
+  //  LayoutNGBlockFlow {BODY} at (8,8) size 784x27
+  //   LayoutNGRubyAsBlock {RUBY} at (0,0) size 784x27
+  //     LayoutNGRubyRun (anonymous) at (0,7) size 22x20
+  //       LayoutNGRubyText {RT} at (0,-10) size 22x12
+  //         LayoutText {#text} at (2,0) size 18x12
+  //           text run at (2,0) width 18: "XYZ"
+  //       LayoutNGRubyBase (anonymous) at (0,0) size 22x20
+  //         LayoutText {#text} at (0,0) size 22x19
+  //           text run at (0,0) width 22: "abc"
+  InsertStyleElement("ruby { display: block; }");
+  EXPECT_EQ("<ruby>^abc|<rt>XYZ</rt></ruby>",
+            GetRange("|<ruby>abc<rt>XYZ</rt></ruby>"));
+  EXPECT_EQ("<ruby>^abc|<rt>XYZ</rt></ruby>",
+            GetRange("<ruby>|abc<rt>XYZ</rt></ruby>"));
+  EXPECT_EQ("<ruby>abc<rt>^XYZ|</rt></ruby>",
+            GetRange("<ruby>abc<rt>|XYZ</rt></ruby>"));
+}
+
+TEST_P(ParameterizedTextOffsetMappingTest, RangeOfBlockWithRubyAsInlineBlock) {
+  InsertStyleElement("ruby { display: inline-block; }");
+  EXPECT_EQ("<ruby>^abc|<rt>XYZ</rt></ruby>",
+            GetRange("|<ruby>abc<rt>XYZ</rt></ruby>"));
+  EXPECT_EQ("<ruby>^abc|<rt>XYZ</rt></ruby>",
+            GetRange("<ruby>|abc<rt>XYZ</rt></ruby>"));
+  EXPECT_EQ("<ruby>abc<rt>^XYZ|</rt></ruby>",
+            GetRange("<ruby>abc<rt>|XYZ</rt></ruby>"));
+}
+
 TEST_P(ParameterizedTextOffsetMappingTest, RangeOfBlockWithRUBYandBR) {
   EXPECT_EQ("<ruby>^abc<br>def|<rt>123<br>456</rt></ruby>",
             GetRange("<ruby>|abc<br>def<rt>123<br>456</rt></ruby>"))