TextControl NG: Fix All/HTMLTextAreaElementTest.ValueWithHardLineBreaks/1 test...

TextControl NG: Fix All/HTMLTextAreaElementTest.ValueWithHardLineBreaks/1 test on linux_layout_tests_layout_ng_disabled bot

HTMLTextAreaElementTest is a parameterized test for LayoutNGTextArea
flag. However, the feature can be disabled even with GetParam() == true
because we can disable LayoutNG flag.

This CL fixes the issue by checking LayoutObject instead of GetParam().

Bug: 1040826
Change-Id: I160037df5b2f52694f96379188724b578fb77d59
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng_disabled
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505343
Auto-Submit: Kent Tamura <tkent@chromium.org>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822031}

third_party/blink/renderer/core/html/forms/html_text_area_element_test.cc

@@ -83,7 +83,8 @@ TEST_P(HTMLTextAreaElementTest, ValueWithHardLineBreaks) {
   inner_editor->appendChild(doc.CreateRawElement(html_names::kBrTag));
   RunDocumentLifecycle();
   // Should be "1234\n5678\n90".  The legacy behavior is wrong.
-  EXPECT_EQ(GetParam() ? "1234\n5678\n90" : "1234567890",
+  EXPECT_EQ(textarea.GetLayoutBox()->IsLayoutNGObject() ? "1234\n5678\n90"
+                                                        : "1234567890",
             textarea.ValueWithHardLineBreaks());
 }