diff --git a/css/css-ui/parsing/form-sizing-computed.html b/css/css-ui/parsing/form-sizing-computed.html
index 557b1d5eb960d4..e508cd2050e3e0 100644
--- a/css/css-ui/parsing/form-sizing-computed.html
+++ b/css/css-ui/parsing/form-sizing-computed.html
@@ -8,7 +8,7 @@
 <body>
 <div id="target"></div>
 <script>
-test_computed_value('form-sizing', 'auto');
-test_computed_value('form-sizing', 'normal');
+test_computed_value('form-sizing', 'fixed');
+test_computed_value('form-sizing', 'content');
 </script>
 </body>
diff --git a/css/css-ui/parsing/form-sizing-invalid.html b/css/css-ui/parsing/form-sizing-invalid.html
index 80ab546f90e1ea..5589707b25e32d 100644
--- a/css/css-ui/parsing/form-sizing-invalid.html
+++ b/css/css-ui/parsing/form-sizing-invalid.html
@@ -9,6 +9,8 @@
 <script>
 test_invalid_value('form-sizing', 'none');
 test_invalid_value('form-sizing', 'legacy');
+test_invalid_value('form-sizing', 'auto');
+test_invalid_value('form-sizing', 'normal');
 test_invalid_value('form-sizing', 'normal auto');
 test_invalid_value('form-sizing', '100%');
 test_invalid_value('form-sizing', '10px');
diff --git a/css/css-ui/parsing/form-sizing-valid.html b/css/css-ui/parsing/form-sizing-valid.html
index f7cc8f44c3cc06..d9d39f79132dc4 100644
--- a/css/css-ui/parsing/form-sizing-valid.html
+++ b/css/css-ui/parsing/form-sizing-valid.html
@@ -7,7 +7,7 @@
 <script src="/css/support/parsing-testcommon.js"></script>
 <body>
 <script>
-test_valid_value('form-sizing', 'auto');
-test_valid_value('form-sizing', 'normal');
+test_valid_value('form-sizing', 'fixed');
+test_valid_value('form-sizing', 'content');
 </script>
 </body>
diff --git a/html/rendering/widgets/form-sizing-input-number.tentative.html b/html/rendering/widgets/form-sizing-input-number.tentative.html
index 59835805a07148..0bf64c181d0f1e 100644
--- a/html/rendering/widgets/form-sizing-input-number.tentative.html
+++ b/html/rendering/widgets/form-sizing-input-number.tentative.html
@@ -4,7 +4,7 @@
 <script src="/resources/testharnessreport.js"></script>
 <style>
 .disable-default {
-  form-sizing: normal;
+  form-sizing: content;
 }
 
 .small-placeholder {
@@ -51,7 +51,7 @@
   test(() => {
     let pair = addElements(`<input type=${type}>`);
     // A text <input> has approximately 20ch width by default.
-    // A text <input> with form-sizing:normal must be shorter than the default.
+    // A text <input> with form-sizing:content must be shorter than the default.
     assert_less_than(pair.content.offsetWidth, pair.fixed.offsetWidth);
     assert_equals(pair.content.offsetHeight, pair.fixed.offsetHeight);
 
diff --git a/html/rendering/widgets/form-sizing-input-text.tentative.html b/html/rendering/widgets/form-sizing-input-text.tentative.html
index 32cabc557f6fc2..065994471f0286 100644
--- a/html/rendering/widgets/form-sizing-input-text.tentative.html
+++ b/html/rendering/widgets/form-sizing-input-text.tentative.html
@@ -4,7 +4,7 @@
 <script src="/resources/testharnessreport.js"></script>
 <style>
 .disable-default {
-  form-sizing: normal;
+  form-sizing: content;
 }
 
 .small-placeholder {
@@ -50,7 +50,7 @@
   test(() => {
     let pair = addElements(`<input type=${type}>`);
     // A text <input> has approximately 20ch width by default.
-    // A text <input> with form-sizing:normal must be shorter than the default.
+    // A text <input> with form-sizing:content must be shorter than the default.
     assert_less_than(pair.content.offsetWidth, pair.fixed.offsetWidth);
     assert_equals(pair.content.offsetHeight, pair.fixed.offsetHeight);
 
diff --git a/html/rendering/widgets/form-sizing-select.tentative.html b/html/rendering/widgets/form-sizing-select.tentative.html
index f9efdc74f9145b..7ce6f03ff4bd3f 100644
--- a/html/rendering/widgets/form-sizing-select.tentative.html
+++ b/html/rendering/widgets/form-sizing-select.tentative.html
@@ -5,7 +5,7 @@
 <body>
 <style>
 .disable-default {
-  form-sizing: normal;
+  form-sizing: content;
 }
 </style>
 <div id="container"></div>
@@ -18,7 +18,7 @@
 test(() => {
   const s = '<select>><option>1<option>quick brown<option>fox</select>';
   container.innerHTML = s + s;
-  container.lastElementChild.style.formSizing = 'normal';
+  container.lastElementChild.style.formSizing = 'content';
   const widthForContent1 = container.lastElementChild.offsetWidth;
   assert_greater_than(container.firstElementChild.offsetWidth,
                       widthForContent1);
@@ -31,9 +31,9 @@
   container.innerHTML = '<select><option>foo<option>quick brown fox</select>';
   const select = container.firstElementChild;
   const initialWidth = select.offsetWidth;
-  select.style.formSizing = 'normal';
+  select.style.formSizing = 'content';
   assert_less_than(select.offsetWidth, initialWidth);
-  select.style.formSizing = 'auto';
+  select.style.formSizing = 'fixed';
   assert_equals(select.offsetWidth, initialWidth);
 }, 'dropdown: Change the form-sizing value dynamically');
 
@@ -76,9 +76,9 @@
     container.innerHTML = '<select multiple><option>foo<option>quick brown fox</select>';
     const select = container.firstElementChild;
     const initialHeight = select.offsetHeight;
-    select.style.formSizing = 'normal';
+    select.style.formSizing = 'content';
     assert_less_than(select.offsetHeight, initialHeight);
-    select.style.formSizing = 'auto';
+    select.style.formSizing = 'fixed';
     assert_equals(select.offsetHeight, initialHeight);
   }, 'listbox: Change the form-sizing value dynamically');
 
diff --git a/html/rendering/widgets/form-sizing-textarea.tentative.html b/html/rendering/widgets/form-sizing-textarea.tentative.html
index ae20e59290c7d4..fb4ce762e32310 100644
--- a/html/rendering/widgets/form-sizing-textarea.tentative.html
+++ b/html/rendering/widgets/form-sizing-textarea.tentative.html
@@ -4,7 +4,7 @@
 <script src="/resources/testharnessreport.js"></script>
 <style>
 .disable-default {
-  form-sizing: normal;
+  form-sizing: content;
 }
 
 .small-placeholder {
@@ -49,7 +49,7 @@
 test(() => {
   let pair = addElements('<textarea></textarea>');
   // Historically a <textarea> has approximately 20ch x 2lh size by default.
-  // A <textarea> with form-sizing:normal must be samller than the default.
+  // A <textarea> with form-sizing:content must be samller than the default.
   assert_less_than(pair.content.offsetWidth, pair.fixed.offsetWidth);
   assert_less_than(pair.content.offsetHeight, pair.fixed.offsetHeight);
 
