LibWeb: Break friendship between CSS Function and Parser

Again, this means deviating from the spec by creating a complete
Function in one go instead of creating it empty and then poking at its
internals.

Userland/Libraries/LibWeb/CSS/Parser/Function.cpp

@@ -10,11 +10,6 @@
 
 namespace Web::CSS::Parser {
 
-Function::Function(FlyString name)
-    : m_name(move(name))
-{
-}
-
 Function::Function(FlyString name, Vector<ComponentValue>&& values)
     : m_name(move(name))
     , m_values(move(values))

Userland/Libraries/LibWeb/CSS/Parser/Function.h

@@ -17,11 +17,12 @@
 namespace Web::CSS::Parser {
 
 class Function : public RefCounted<Function> {
-    friend class Parser;
-
 public:
-    explicit Function(FlyString name);
-    Function(FlyString name, Vector<ComponentValue>&& values);
+    static NonnullRefPtr<Function> create(FlyString name, Vector<ComponentValue>&& values)
+    {
+        return adopt_ref(*new Function(move(name), move(values)));
+    }
+
     ~Function();
 
     StringView name() const { return m_name; }
@@ -30,6 +31,8 @@ public:
     String to_string() const;
 
 private:
+    Function(FlyString name, Vector<ComponentValue>&& values);
+
     FlyString m_name;
     Vector<ComponentValue> m_values;
 };

Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp

@@ -1878,7 +1878,9 @@ NonnullRefPtr<Function> Parser::consume_a_function(TokenStream<T>& tokens)
 
     // Create a function with its name equal to the value of the current input token
     // and with its value initially set to an empty list.
-    auto function = make_ref_counted<Function>(((Token)name_ident).function());
+    // NOTE: We create the Function fully initialized when we return it instead.
+    FlyString function_name = ((Token)name_ident).function();
+    Vector<ComponentValue> function_values;
 
     // Repeatedly consume the next input token and process it as follows:
     for (;;) {
@@ -1887,14 +1889,14 @@ NonnullRefPtr<Function> Parser::consume_a_function(TokenStream<T>& tokens)
         // <)-token>
         if (token.is(Token::Type::CloseParen)) {
             // Return the function.
-            return function;
+            return Function::create(move(function_name), move(function_values));
         }
 
         // <EOF-token>
         if (token.is(Token::Type::EndOfFile)) {
             // This is a parse error. Return the function.
             log_parse_error();
-            return function;
+            return Function::create(move(function_name), move(function_values));
         }
 
         // anything else
@@ -1903,7 +1905,7 @@ NonnullRefPtr<Function> Parser::consume_a_function(TokenStream<T>& tokens)
             tokens.reconsume_current_input_token();
 
             // Consume a component value and append the returned value to the function’s value.
-            function->m_values.append(consume_a_component_value(tokens));
+            function_values.append(consume_a_component_value(tokens));
         }
     }
 }

Userland/Libraries/LibWeb/CSS/StyleComputer.cpp

@@ -622,7 +622,7 @@ bool StyleComputer::expand_unresolved_values(DOM::Element& element, StringView p
             Vector<Parser::ComponentValue> function_values;
             if (!expand_unresolved_values(element, property_name, dependencies, source_function.values(), function_values, 0))
                 return false;
-            NonnullRefPtr<Parser::Function> function = adopt_ref(*new Parser::Function(source_function.name(), move(function_values)));
+            NonnullRefPtr<Parser::Function> function = Parser::Function::create(source_function.name(), move(function_values));
             dest.empend(function);
             continue;
         }