From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Anders Hartvoll Ruud <[email protected]>

Date: Wed, 25 Feb 2026 03:25:14 -0800

Subject: Stringify CSSUnparsedValues via toString, as normal

CSSUnparsedValue exposes a special stringification function

ToUnparsedString() in addition to the regular toString().

The documentation says it returns "tokens without substituting

variables", but it's not clear what this means; we don't substitute

any variables in CSSStyleValue::toString() either.

This CL makes ToUnparsedString() private (and renames it).

Clients needing to serialize a CSSUnparsedValue can do so via

the normal toString() function. (If ToUnparsedString() existed

for performance reasons, that should have been documented.)

Also, the /**/-"fixup" pass over the value has been folded into

ToStringInternal(). This is to make it easy to find the canonical string

representation of this value within CSSUnparsedValue (without going

through a CSSValue).

The main point of this CL is to prepare for validating

the "argument grammar" of the value during the StyleValue-to-CSSValue

conversion in StylePropertyMap (which requires item (2) above).

We now jump through additional hoops to ultimately get a string

from the outside of CSSUnparsedValue, but there should otherwise

be no behavior change.

Bug: 484751092

Change-Id: I5db45ad85f780c67a2ea3ba8482c390ebab10068

Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7600415

Commit-Queue: Anders Hartvoll Ruud <[email protected]>

Reviewed-by: Steinar H Gunderson <[email protected]>

Cr-Commit-Position: refs/heads/main@{#1590041}

index dcc2eccbc84e6cd5710ab51cee2dab49661467c1..86d42c87a6bd10838a3e059c9227868e5bfc0798 100644

#include "third_party/blink/renderer/core/css/cssom/css_keyword_value.h"

#include "third_party/blink/renderer/core/css/cssom/css_style_value.h"

#include "third_party/blink/renderer/core/css/cssom/css_unit_value.h"

#include "third_party/blink/renderer/core/css/cssom/css_unsupported_color.h"

#include "third_party/blink/renderer/platform/scheduler/public/non_main_thread.h"

#include "third_party/blink/renderer/platform/scheduler/public/post_cross_thread_task.h"

#include "third_party/blink/renderer/platform/wtf/cross_thread_copier_std.h"

#include "third_party/blink/renderer/platform/wtf/cross_thread_functional.h"

namespace blink {

@@ -152,8 +152,7 @@ TEST_F(CrossThreadStyleValueTest, CrossThreadUnparsedValueToCSSStyleValue) {

CSSStyleValue* style_value = value->ToCSSStyleValue();

EXPECT_EQ(style_value->GetType(),

CSSStyleValue::StyleValueType::kUnparsedType);

}

TEST_F(CrossThreadStyleValueTest, PassKeywordValueCrossThread) {

index 67a4afde452f94ffb9ecbaeea104a3997c65b7b3..9c6bb62d044f804b0ce7bc8df398d77695cf950c 100644

@@ -124,16 +124,26 @@ IndexedPropertySetterResult CSSUnparsedValue::AnonymousIndexedSetter(

}

const CSSValue* CSSUnparsedValue::ToCSSValue() const {

return MakeGarbageCollected<CSSUnparsedDeclarationValue>(

MakeGarbageCollected<CSSVariableData>());

}

// The spec mentions nothing of the sort:

// https://drafts.css-houdini.org/css-typed-om-1/#unparsedvalue-serialization

//

@@ -147,6 +157,10 @@ const CSSValue* CSSUnparsedValue::ToCSSValue() const {

// the original contents of any comments will be lost, but Typed OM does

// not have anywhere to store that kind of data, so it is expected.

StringBuilder builder;

CSSParserToken token = stream.ConsumeRaw();

token.Serialize(builder);

while (!stream.Peek().IsEOF()) {

@@ -156,17 +170,10 @@ const CSSValue* CSSUnparsedValue::ToCSSValue() const {

token = stream.ConsumeRaw();

token.Serialize(builder);

}

}

StringBuilder builder;

HeapHashSet<Member<const CSSUnparsedValue>> values_on_stack;

if (AppendUnparsedString(builder, values_on_stack)) {

index 5d1961b170f14ae21ca8f69b3c3cd8af28f4478a..ec7e3ed708f406d7a61fdb370b2eed8a8297cffb 100644

@@ -67,15 +67,9 @@ class CORE_EXPORT CSSUnparsedValue final : public CSSStyleValue {

CSSStyleValue::Trace(visitor);

}

private:

// Return 'false' if there is a cycle in the serialization.

bool AppendUnparsedString(

StringBuilder&,

index f81fa39423a9235bc58e1600ca7a250affd3d9bb..2ee4dd7e591095b8460ca559b29b78e37ab71729 100644

#include "third_party/blink/renderer/core/css/cssom/paint_worklet_style_property_map.h"

#include <memory>

#include "base/synchronization/waitable_event.h"

#include "base/task/single_thread_task_runner.h"

#include "testing/gtest/include/gtest/gtest.h"

#include "third_party/blink/renderer/core/css/cssom/css_keyword_value.h"

#include "third_party/blink/renderer/core/css/cssom/css_paint_worklet_input.h"

#include "third_party/blink/renderer/core/css/cssom/css_unit_value.h"

#include "third_party/blink/renderer/core/css/cssom/css_unsupported_color.h"

#include "third_party/blink/renderer/core/css/properties/longhands/custom_property.h"

#include "third_party/blink/renderer/core/dom/element.h"

#include "third_party/blink/renderer/platform/scheduler/public/post_cross_thread_task.h"

#include "third_party/blink/renderer/platform/wtf/cross_thread_copier_base.h"

#include "third_party/blink/renderer/platform/wtf/cross_thread_functional.h"

namespace blink {

@@ -66,8 +67,7 @@ class PaintWorkletStylePropertyMapTest : public PageTestBase {

CSSStyleValue* style_value = data.at("--x")->ToCSSStyleValue();

EXPECT_EQ(style_value->GetType(),

CSSStyleValue::StyleValueType::kUnparsedType);

waitable_event->Signal();

}

index 1db0fd72478d708008f1b95a6aff206b28f60a6a..b52d8065c770aba822e9977c251c540643972629 100644

@@ -4872,7 +4872,7 @@ ComputedStyleUtils::CrossThreadStyleValueFromCSSStyleValue(

To<CSSUnsupportedColor>(style_value)->Value());

case CSSStyleValue::StyleValueType::kUnparsedType:

return std::make_unique<CrossThreadUnparsedValue>(

default:

return std::make_unique<CrossThreadUnsupportedValue>(

style_value->toString());