input[type=file]: Ignore the 'overflow' property

For a historical reason, some form controls always clip the content,
and should ignore the 'overflow' property. File upload control NG had
a regression that it accepts overflow:visible.  This CL disables it
again. The new behavior is compatible with Safari and Firefox.

Bug: 1139629
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng_disabled
Change-Id: I6b0b5a715a2c859f195bbf2473ead67cd22bd14d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2528812Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825813}

third_party/blink/renderer/core/html/resources/html.css

@@ -567,7 +567,7 @@ input[type="hidden" i], input[type="image" i], input[type="file" i] {
 input[type="file" i] {
     align-items: baseline;
     color: inherit;
-    overflow: hidden;
+    overflow: hidden !important;
     text-align: start !important;
     text-overflow: ellipsis;
     white-space: pre;

third_party/blink/web_tests/fast/forms/file/file-appearance-basic.html

@@ -71,4 +71,15 @@ Styling ::-webkit-file-upload-button:
 <input type=file class="button-shadow">
 <div>
 
+<div>
+<style>
+.overflow {
+  overflow: visible;
+  width: 10px;
+}
+</style>
+'overflow: visible' should not work:
+<input type=file class=overflow>
+</div>
+
 </body>