Align some set innerText behavior with standard

According to spec[1], when a string starts with CR/LF set as innerText,
the first child node should not be an empty text node. So we adjust the
logic in HTMLElement::TextToFragment to make sure it follows the spec.

Besides, same in spec[1], there is no special procedure for setting
innerText when the element is being rendered and styled as preserving
new line, so corresponding code was removed in this commit.

15 failed wpt tests could be passed after this change.

[1] https://html.spec.whatwg.org/multipage/dom.html#the-innertext-idl-attribute

Bug: 573309, 705478
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng;luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I6765601a14c2e95cec3841e084046da79aca065c
Reviewed-on: https://chromium-review.googlesource.com/c/1266728Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601480}

third_party/WebKit/LayoutTests/external/wpt/html/dom/elements/the-innertext-idl-attribute/setter-expected.txt

 This is a testharness.js-based test.
-Found 126 tests; 80 PASS, 46 FAIL, 0 TIMEOUT, 0 NOTRUN.
+Found 126 tests; 95 PASS, 31 FAIL, 0 TIMEOUT, 0 NOTRUN.
 PASS Simplest possible test
 PASS Simplest possible test, detached
 PASS Newlines convert to <br> in non-white-space:pre elements
 PASS Newlines convert to <br> in non-white-space:pre elements, detached
-FAIL Newlines convert to <br> in <pre> element assert_equals: expected "abc<br>def" but got "abc\ndef"
+PASS Newlines convert to <br> in <pre> element
 PASS Newlines convert to <br> in <pre> element, detached
-FAIL Newlines convert to <br> in <textarea> element assert_equals: expected "abc<br>def" but got "abc\ndef"
+PASS Newlines convert to <br> in <textarea> element
 PASS Newlines convert to <br> in <textarea> element, detached
-FAIL Newlines convert to <br> in white-space:pre element assert_equals: expected "abc<br>def" but got "abc\ndef"
+PASS Newlines convert to <br> in white-space:pre element
 PASS Newlines convert to <br> in white-space:pre element, detached
 PASS CRs convert to <br> in non-white-space:pre elements
 PASS CRs convert to <br> in non-white-space:pre elements, detached
-FAIL CRs convert to <br> in <pre> element assert_equals: expected "abc<br>def" but got "abc\ndef"
+PASS CRs convert to <br> in <pre> element
 PASS CRs convert to <br> in <pre> element, detached
 PASS Newline/CR pair converts to <br> in non-white-space:pre element
 PASS Newline/CR pair converts to <br> in non-white-space:pre element, detached
-FAIL Newline/newline pair converts to two <br>s in non-white-space:pre element assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL Newline/newline pair converts to two <br>s in non-white-space:pre element, detached assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL CR/CR pair converts to two <br>s in non-white-space:pre element assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL CR/CR pair converts to two <br>s in non-white-space:pre element, detached assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL CRs convert to <br> in white-space:pre element assert_equals: expected "abc<br>def" but got "abc\ndef"
+PASS Newline/newline pair converts to two <br>s in non-white-space:pre element
+PASS Newline/newline pair converts to two <br>s in non-white-space:pre element, detached
+PASS CR/CR pair converts to two <br>s in non-white-space:pre element
+PASS CR/CR pair converts to two <br>s in non-white-space:pre element, detached
+PASS CRs convert to <br> in white-space:pre element
 PASS CRs convert to <br> in white-space:pre element, detached
 PASS < preserved
 PASS < preserved, detached
@@ -56,12 +56,12 @@ PASS Assigning null
 PASS Assigning null, detached
 PASS Assigning undefined
 PASS Assigning undefined, detached
-FAIL Start with CR assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL Start with CR, detached assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL Start with LF assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL Start with LF, detached assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL Start with CRLF assert_not_equals: Should not have empty text nodes got disallowed value ""
-FAIL Start with CRLF, detached assert_not_equals: Should not have empty text nodes got disallowed value ""
+PASS Start with CR
+PASS Start with CR, detached
+PASS Start with LF
+PASS Start with LF, detached
+PASS Start with CRLF
+PASS Start with CRLF, detached
 PASS End with CR
 PASS End with CR, detached
 PASS End with LF

third_party/blink/renderer/core/html/html_element.cc

@@ -626,22 +626,26 @@ DocumentFragment* HTMLElement::TextToFragment(const String& text,
         break;
     }
 
-    fragment->AppendChild(
-        Text::Create(GetDocument(), text.Substring(start, i - start)),
-        exception_state);
-    if (exception_state.HadException())
-      return nullptr;
-
-    if (c == '\r' || c == '\n') {
-      fragment->AppendChild(HTMLBRElement::Create(GetDocument()),
-                            exception_state);
+    if (i > start) {
+      fragment->AppendChild(
+          Text::Create(GetDocument(), text.Substring(start, i - start)),
+          exception_state);
       if (exception_state.HadException())
         return nullptr;
-      // Make sure \r\n doesn't result in two line breaks.
-      if (c == '\r' && i + 1 < length && text[i + 1] == '\n')
-        i++;
     }
 
+    if (i == length)
+      break;
+
+    fragment->AppendChild(HTMLBRElement::Create(GetDocument()),
+                          exception_state);
+    if (exception_state.HadException())
+      return nullptr;
+
+    // Make sure \r\n doesn't result in two line breaks.
+    if (c == '\r' && i + 1 < length && text[i + 1] == '\n')
+      i++;
+
     start = i + 1;  // Character after line break.
   }
 
@@ -661,25 +665,6 @@ void HTMLElement::setInnerText(const String& text,
     return;
   }
 
-  // FIXME: Do we need to be able to detect preserveNewline style even when
-  // there's no layoutObject?
-  // FIXME: Can the layoutObject be out of date here? Do we need to call
-  // updateStyleIfNeeded?  For example, for the contents of textarea elements
-  // that are display:none?
-  LayoutObject* r = GetLayoutObject();
-  if (r && r->Style()->PreserveNewline()) {
-    if (!text.Contains('\r')) {
-      ReplaceChildrenWithText(this, text, exception_state);
-      return;
-    }
-    String text_with_consistent_line_breaks = text;
-    text_with_consistent_line_breaks.Replace("\r\n", "\n");
-    text_with_consistent_line_breaks.Replace('\r', '\n');
-    ReplaceChildrenWithText(this, text_with_consistent_line_breaks,
-                            exception_state);
-    return;
-  }
-
   // Add text nodes and <br> elements.
   DocumentFragment* fragment = TextToFragment(text, exception_state);
   if (!exception_state.HadException())