Get rid ot unused function TextIteratorBehavior::CollapseTrailingSpace()

This patch gets rid of unused function |CollapseTrailingSpace()| in
|TextIteratorBehavior| and related things for improving code health.

Note: This patch doesn't change behaviors.

Note: This patch exposes differences between legacy and LayoutNG about trailing
space to help implementing EditingNG. The legacy layout tree holds trailing
spaces, e.g. "ab  <br>cd", but LayoutNG doesn't.

Bug: 707656
Change-Id: Ib7c5c4a1be39bb7f50d0aa9378e8d1148e682d18
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2167633
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Auto-Submit: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762742}

third_party/blink/renderer/core/editing/iterators/text_iterator_behavior.cc

@@ -16,12 +16,6 @@ TextIteratorBehavior TextIteratorBehavior::Builder::Build() {
   return behavior_;
 }
 
-TextIteratorBehavior::Builder&
-TextIteratorBehavior::Builder::SetCollapseTrailingSpace(bool value) {
-  behavior_.values_.bits.collapse_trailing_space = value;
-  return *this;
-}
-
 TextIteratorBehavior::Builder&
 TextIteratorBehavior::Builder::SetDoesNotBreakAtReplacedElement(bool value) {
   behavior_.values_.bits.does_not_break_at_replaced_element = value;

third_party/blink/renderer/core/editing/iterators/text_iterator_behavior.h

@@ -23,9 +23,6 @@ class CORE_EXPORT TextIteratorBehavior final {
   bool operator==(const TextIteratorBehavior& other) const;
   bool operator!=(const TextIteratorBehavior& other) const;
 
-  bool CollapseTrailingSpace() const {
-    return values_.bits.collapse_trailing_space;
-  }
   bool DoesNotBreakAtReplacedElement() const {
     return values_.bits.does_not_break_at_replaced_element;
   }
@@ -83,7 +80,6 @@ class CORE_EXPORT TextIteratorBehavior final {
   union {
     unsigned all;
     struct {
-      bool collapse_trailing_space : 1;
       bool does_not_break_at_replaced_element : 1;
       bool emits_characters_between_all_visible_positions : 1;
       bool emits_image_alt_text : 1;
@@ -117,7 +113,6 @@ class CORE_EXPORT TextIteratorBehavior::Builder final {
 
   TextIteratorBehavior Build();
 
-  Builder& SetCollapseTrailingSpace(bool);
   Builder& SetDoesNotBreakAtReplacedElement(bool);
   Builder& SetEmitsCharactersBetweenAllVisiblePositions(bool);
   Builder& SetEmitsImageAltText(bool);

third_party/blink/renderer/core/editing/iterators/text_iterator_behavior_test.cc

@@ -11,33 +11,25 @@ namespace blink {
 TEST(TextIteratorBehaviorTest, Basic) {
   EXPECT_TRUE(TextIteratorBehavior() == TextIteratorBehavior());
   EXPECT_FALSE(TextIteratorBehavior() != TextIteratorBehavior());
-  EXPECT_NE(
-      TextIteratorBehavior(),
-      TextIteratorBehavior::Builder().SetCollapseTrailingSpace(true).Build());
-  EXPECT_NE(
-      TextIteratorBehavior::Builder().SetCollapseTrailingSpace(true).Build(),
-      TextIteratorBehavior());
-  EXPECT_NE(
-      TextIteratorBehavior::Builder().SetCollapseTrailingSpace(true).Build(),
-      TextIteratorBehavior::Builder().SetEmitsImageAltText(true).Build());
-  EXPECT_NE(
-      TextIteratorBehavior::Builder().SetEmitsImageAltText(true).Build(),
-      TextIteratorBehavior::Builder().SetCollapseTrailingSpace(true).Build());
+  EXPECT_NE(TextIteratorBehavior(),
+            TextIteratorBehavior::Builder().SetForInnerText(true).Build());
+  EXPECT_NE(TextIteratorBehavior::Builder().SetForInnerText(true).Build(),
+            TextIteratorBehavior());
+  EXPECT_NE(TextIteratorBehavior::Builder().SetForInnerText(true).Build(),
+            TextIteratorBehavior::Builder().SetEmitsImageAltText(true).Build());
+  EXPECT_NE(TextIteratorBehavior::Builder().SetEmitsImageAltText(true).Build(),
+            TextIteratorBehavior::Builder().SetForInnerText(true).Build());
   EXPECT_EQ(TextIteratorBehavior::Builder()
-                .SetCollapseTrailingSpace(true)
+                .SetForInnerText(true)
                 .SetEmitsImageAltText(true)
                 .Build(),
             TextIteratorBehavior::Builder()
                 .SetEmitsImageAltText(true)
-                .SetCollapseTrailingSpace(true)
+                .SetForInnerText(true)
                 .Build());
 }
 
 TEST(TextIteratorBehaviorTest, Values) {
-  EXPECT_TRUE(TextIteratorBehavior::Builder()
-                  .SetCollapseTrailingSpace(true)
-                  .Build()
-                  .CollapseTrailingSpace());
   EXPECT_TRUE(TextIteratorBehavior::Builder()
                   .SetDoesNotBreakAtReplacedElement(true)
                   .Build()

third_party/blink/renderer/core/editing/iterators/text_iterator_test.cc

@@ -43,10 +43,6 @@
 namespace blink {
 namespace text_iterator_test {
 
-TextIteratorBehavior CollapseTrailingSpaceBehavior() {
-  return TextIteratorBehavior::Builder().SetCollapseTrailingSpace(true).Build();
-}
-
 TextIteratorBehavior EmitsImageAltTextBehavior() {
   return TextIteratorBehavior::Builder().SetEmitsImageAltText(true).Build();
 }
@@ -544,16 +540,41 @@ TEST_P(TextIteratorTest, RangeLengthWithFirstLetterMultipleLeadingSpaces) {
   EXPECT_EQ(3, TestRangeLength("<p>^   foo|</p>"));
 }
 
+TEST_P(TextIteratorTest, TrainlingSpace) {
+  // text_content = "ab\ncd"
+  // offset mapping units:
+  //   [0] I DOM:0-2 TC:0-2 "ab"
+  //   [1] C DOM:2-4 TC:2-2 " " spaces after "ab"
+  //   [2] I DOM:0-1 TC:2-3 <br>
+  //   [3] I DOM:0-2 TC:3-5 "cd"
+  // Note: InlineTextBox has trailing spaces which we should get rid from
+  // inline layout tree as LayoutNG.
+  SetBodyContent("ab  <br>  cd");
+  EXPECT_EQ(LayoutNGEnabled() ? "[ab][\n][cd]" : "[ab ][\n][cd]",
+            Iterate<DOMTree>());
+}
+
 TEST_P(TextIteratorTest, WhitespaceCollapseForReplacedElements) {
   static const char* body_content =
       "<span>Some text </span> <input type='button' value='Button "
       "text'/><span>Some more text</span>";
   SetBodyContent(body_content);
-  EXPECT_EQ("[Some text ][][Some more text]",
-            Iterate<DOMTree>(CollapseTrailingSpaceBehavior()));
+  // text_content = "Some text \uFFFCSome more text"
+  // offset mapping units:
+  //   [0] I DOM:0-10 TC:0-10 "Some text "
+  //   [1] C DOM:0-1  TC:10-10 " " (A space between </span> and <input>
+  //   [2] I DOM:0-1  TC:10-11 <input> as U+FFFC (ORC)
+  //   [3] I DOM:0-14 TC:11-25 "Some more text"
+  // Note: InlineTextBox has a collapsed space which we should get rid from
+  // inline layout tree as LayoutNG.
+  EXPECT_EQ(LayoutNGEnabled() ? "[Some text ][][Some more text]"
+                              : "[Some text ][ ][][Some more text]",
+            Iterate<DOMTree>());
   // <input type=button> is not text control element
-  EXPECT_EQ("[Some text ][][Button text][Some more text]",
-            Iterate<FlatTree>(CollapseTrailingSpaceBehavior()));
+  EXPECT_EQ(LayoutNGEnabled()
+                ? "[Some text ][][Button text][Some more text]"
+                : "[Some text ][ ][][Button text][Some more text]",
+            Iterate<FlatTree>());
 }
 
 TEST_P(TextIteratorTest, characterAt) {

third_party/blink/renderer/core/editing/iterators/text_iterator_text_node_handler.cc

@@ -178,12 +178,9 @@ void TextIteratorTextNodeHandler::HandlePreFormattedTextNode() {
 
   if (last_text_node_ended_with_collapsed_space_ &&
       HasVisibleTextNode(layout_object)) {
-    if (!behavior_.CollapseTrailingSpace() ||
-        (offset_ > 0 && str[offset_ - 1] == ' ')) {
-      EmitChar16Before(kSpaceCharacter, offset_);
-      needs_handle_pre_formatted_text_node_ = true;
-      return;
-    }
+    EmitChar16Before(kSpaceCharacter, offset_);
+    needs_handle_pre_formatted_text_node_ = true;
+    return;
   }
   if (ShouldHandleFirstLetter(*layout_object)) {
     LayoutTextFragment* remaining_text = ToLayoutTextFragment(layout_object);
@@ -545,12 +542,7 @@ bool TextIteratorTextNodeHandler::ShouldFixLeadingWhiteSpaceForReplacedElement()
     return false;
   if (!last_text_node_ended_with_collapsed_space_)
     return false;
-  if (!behavior_.CollapseTrailingSpace())
-    return true;
-  if (!text_node_)
-    return false;
-  const String str = text_node_->GetLayoutObject()->GetText();
-  return offset_ > 0 && str[offset_ - 1] == ' ';
+  return true;
 }
 
 bool TextIteratorTextNodeHandler::FixLeadingWhiteSpaceForReplacedElement() {