LibWeb: Port ProcessingInstruction from ByteString

Userland/Libraries/LibWeb/DOM/Document.cpp

@@ -1427,7 +1427,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<ProcessingInstruction>> Document::create_pr
     // FIXME: 2. If data contains the string "?>", then throw an "InvalidCharacterError" DOMException.
 
     // 3. Return a new ProcessingInstruction node, with target set to target, data set to data, and node document set to this.
-    return heap().allocate<ProcessingInstruction>(realm(), *this, data.to_byte_string(), target.to_byte_string());
+    return heap().allocate<ProcessingInstruction>(realm(), *this, data, target);
 }
 
 JS::NonnullGCPtr<Range> Document::create_range()

Userland/Libraries/LibWeb/DOM/Node.cpp

@@ -872,7 +872,7 @@ JS::NonnullGCPtr<Node> Node::clone_node(Document* document, bool clone_children)
         auto processing_instruction = verify_cast<ProcessingInstruction>(this);
 
         // Set copy’s target and data to those of node.
-        auto processing_instruction_copy = heap().allocate<ProcessingInstruction>(realm(), *document, processing_instruction->data().to_byte_string(), processing_instruction->target());
+        auto processing_instruction_copy = heap().allocate<ProcessingInstruction>(realm(), *document, processing_instruction->data(), processing_instruction->target());
         copy = processing_instruction_copy;
     }
     // Otherwise, Do nothing.

Userland/Libraries/LibWeb/DOM/ProcessingInstruction.cpp

@@ -13,8 +13,8 @@ namespace Web::DOM {
 
 JS_DEFINE_ALLOCATOR(ProcessingInstruction);
 
-ProcessingInstruction::ProcessingInstruction(Document& document, ByteString const& data, ByteString const& target)
-    : CharacterData(document, NodeType::PROCESSING_INSTRUCTION_NODE, MUST(String::from_byte_string(data)))
+ProcessingInstruction::ProcessingInstruction(Document& document, String const& data, String const& target)
+    : CharacterData(document, NodeType::PROCESSING_INSTRUCTION_NODE, data)
     , m_target(target)
 {
 }

Userland/Libraries/LibWeb/DOM/ProcessingInstruction.h

@@ -17,16 +17,16 @@ class ProcessingInstruction final : public CharacterData {
 public:
     virtual ~ProcessingInstruction() override = default;
 
-    virtual FlyString node_name() const override { return MUST(FlyString::from_deprecated_fly_string(m_target)); }
+    virtual FlyString node_name() const override { return m_target; }
 
-    ByteString const& target() const { return m_target; }
+    String const& target() const { return m_target; }
 
 private:
-    ProcessingInstruction(Document&, ByteString const& data, ByteString const& target);
+    ProcessingInstruction(Document&, String const& data, String const& target);
 
     virtual void initialize(JS::Realm&) override;
 
-    ByteString m_target;
+    String m_target;
 };
 
 template<>