Add a CrossThreadCopier in CSSSyntaxDescriptor

Current the RegisterMainThreadDocumentPaintDefinition is taking a
std::unique_ptr<Vector<CSSSyntaxDescriptor>> because the
CrossThreadCopier doesn't yet know how to handle a Vectof of
CSSSyntaxDescriptor.

This CL adds a CrossThreadCopier template in the css_syntax_descriptor.h
so that we no longer need to wrap the Vector<CSSSyntaxDescriptor> into
a std::unique_ptr. We add this template in the specific header file
such that it won't pollute the cross_thread_copier.h.

This CL does not change behavior.

Bug: None
Change-Id: Idcad4f578f44605cf535598713e3c03c5035b7aa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1642957Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666089}

third_party/blink/renderer/core/css/css_syntax_descriptor.h

@@ -7,6 +7,7 @@
 
 #include "third_party/blink/renderer/core/css/css_syntax_component.h"
 #include "third_party/blink/renderer/core/css/parser/css_parser_token_range.h"
+#include "third_party/blink/renderer/platform/cross_thread_copier.h"
 
 namespace blink {
 
@@ -48,6 +49,19 @@ class CORE_EXPORT CSSSyntaxDescriptor {
   Vector<CSSSyntaxComponent> syntax_components_;
 };
 
+template <wtf_size_t inlineCapacity, typename Allocator>
+struct CrossThreadCopier<
+    Vector<CSSSyntaxDescriptor, inlineCapacity, Allocator>> {
+  using Type = Vector<CSSSyntaxDescriptor, inlineCapacity, Allocator>;
+  static Type Copy(const Type& value) {
+    Type result;
+    result.ReserveInitialCapacity(value.size());
+    for (const auto& element : value)
+      result.push_back(element.IsolatedCopy());
+    return result;
+  }
+};
+
 }  // namespace blink
 
 #endif  // THIRD_PARTY_BLINK_RENDERER_CORE_CSS_CSS_SYNTAX_DESCRIPTOR_H_

third_party/blink/renderer/modules/csspaint/paint_worklet.cc

@@ -149,12 +149,12 @@ void PaintWorklet::RegisterMainThreadDocumentPaintDefinition(
     const String& name,
     Vector<CSSPropertyID> native_properties,
     Vector<String> custom_properties,
-    std::unique_ptr<Vector<CSSSyntaxDescriptor>> input_argument_types,
+    Vector<CSSSyntaxDescriptor> input_argument_types,
     double alpha) {
   DCHECK(!main_thread_document_definition_map_.Contains(name));
   auto definition = std::make_unique<MainThreadDocumentPaintDefinition>(
       std::move(native_properties), std::move(custom_properties),
-      std::move(*input_argument_types), alpha);
+      std::move(input_argument_types), alpha);
   main_thread_document_definition_map_.insert(name, std::move(definition));
   pending_generator_registry_->NotifyGeneratorReady(name);
 }

third_party/blink/renderer/modules/csspaint/paint_worklet.h

@@ -68,7 +68,7 @@ class MODULES_EXPORT PaintWorklet : public Worklet,
       const String& name,
       Vector<CSSPropertyID> native_properties,
       Vector<String> custom_properties,
-      std::unique_ptr<Vector<CSSSyntaxDescriptor>> input_argument_types,
+      Vector<CSSSyntaxDescriptor> input_argument_types,
       double alpha);
   typedef HashMap<String, std::unique_ptr<MainThreadDocumentPaintDefinition>>
       MainThreadDocumentDefinitionMap;

third_party/blink/renderer/modules/csspaint/paint_worklet_proxy_client.cc

@@ -112,17 +112,13 @@ void PaintWorkletProxyClient::RegisterCSSPaintDefinition(
     for (const auto& property : custom_properties)
       passed_custom_properties.push_back(property.GetString());
 
-    Vector<CSSSyntaxDescriptor> passed_input_argument_types;
-    for (const auto& syntax_descriptor : definition->InputArgumentTypes())
-      passed_input_argument_types.push_back(syntax_descriptor.IsolatedCopy());
     PostCrossThreadTask(
         *main_thread_runner_, FROM_HERE,
         CrossThreadBindOnce(
             &PaintWorklet::RegisterMainThreadDocumentPaintDefinition,
             paint_worklet_, name, definition->NativeInvalidationProperties(),
             WTF::Passed(std::move(passed_custom_properties)),
-            std::make_unique<Vector<CSSSyntaxDescriptor>>(
-                passed_input_argument_types),
+            definition->InputArgumentTypes(),
             definition->GetPaintRenderingContext2DSettings()->alpha()));
   }
 }

third_party/blink/renderer/modules/csspaint/paint_worklet_test.cc

@@ -190,7 +190,7 @@ TEST_F(PaintWorkletTest, NativeAndCustomProperties) {
   TestPaintWorklet* paint_worklet_to_test = GetTestPaintWorklet();
   paint_worklet_to_test->RegisterMainThreadDocumentPaintDefinition(
       "foo", native_invalidation_properties, custom_invalidation_properties,
-      std::make_unique<Vector<CSSSyntaxDescriptor>>(), true);
+      Vector<CSSSyntaxDescriptor>(), true);
 
   CSSPaintImageGeneratorImpl* generator =
       MakeGarbageCollected<CSSPaintImageGeneratorImpl>(paint_worklet_to_test,