Apply length conversion flags for incremental styles

Incremental style resolutions never enter ApplyBaseStyleNoCache,
which is where ApplyLengthConversionFlags normally happens. Call this
function for incremental styling as well.

Note: There's already a call to ApplyLengthConversionFlags in
ApplyAnimatedStyle, so there should not be a similar issue for the
base ComputedStyle optimization.

Fixed: 1402548
Change-Id: I8fafb495c52c1c209d9b59b20e472ce489ad560a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4116982
Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1085846}
diff --git a/css/css-values/crashtests/viewport-unit-inline-style-crash.html b/css/css-values/crashtests/viewport-unit-inline-style-crash.html
new file mode 100644
index 0000000..4c38e18
--- /dev/null
+++ b/css/css-values/crashtests/viewport-unit-inline-style-crash.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<title>Don't crash when setting viewport units on inline style</title>
+<link rel="help" href="https://crbug.com/1402548">
+<div id="div">
+  PASS if no crash
+</div>
+<script>
+  div.style.setProperty("margin-bottom", "1px");
+  div.offsetTop;
+  div.style.setProperty("margin-bottom", "1vh");
+</script>