LibWeb: Break friendship between CSS Block and Parser

This means deviating a little from the spec, so that we create a
complete Block in one go instead of creating an empty one and then
poking at its internals.

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

@@ -9,12 +9,12 @@
 
 namespace Web::CSS::Parser {
 
-Block::Block() = default;
 Block::Block(Token token, Vector<ComponentValue>&& values)
     : m_token(move(token))
     , m_values(move(values))
 {
 }
+
 Block::~Block() = default;
 
 String Block::to_string() const

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

@@ -16,11 +16,12 @@
 namespace Web::CSS::Parser {
 
 class Block : public RefCounted<Block> {
-    friend class Parser;
-
 public:
-    Block();
-    Block(Token, Vector<ComponentValue>&&);
+    static NonnullRefPtr<Block> create(Token token, Vector<ComponentValue>&& values)
+    {
+        return adopt_ref(*new Block(move(token), move(values)));
+    }
+
     ~Block();
 
     bool is_curly() const { return m_token.is(Token::Type::OpenCurly); }
@@ -34,6 +35,7 @@ public:
     String to_string() const;
 
 private:
+    Block(Token, Vector<ComponentValue>&&);
     Token m_token;
     Vector<ComponentValue> m_values;
 };

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

@@ -1834,8 +1834,9 @@ NonnullRefPtr<Block> Parser::consume_a_simple_block(TokenStream<T>& tokens)
 
     // Create a simple block with its associated token set to the current input token
     // and with its value initially set to an empty list.
-    auto block = make_ref_counted<Block>();
-    block->m_token = tokens.current_token();
+    // NOTE: We create the Block fully initialized when we return it instead.
+    Token block_token = tokens.current_token();
+    Vector<ComponentValue> block_values;
 
     // Repeatedly consume the next input token and process it as follows:
     for (;;) {
@@ -1844,13 +1845,13 @@ NonnullRefPtr<Block> Parser::consume_a_simple_block(TokenStream<T>& tokens)
         // ending token
         if (token.is(ending_token)) {
             // Return the block.
-            return block;
+            return Block::create(move(block_token), move(block_values));
         }
         // <EOF-token>
         if (token.is(Token::Type::EndOfFile)) {
             // This is a parse error. Return the block.
             log_parse_error();
-            return block;
+            return Block::create(move(block_token), move(block_values));
         }
 
         // anything else
@@ -1859,7 +1860,7 @@ NonnullRefPtr<Block> Parser::consume_a_simple_block(TokenStream<T>& tokens)
             tokens.reconsume_current_input_token();
 
             // Consume a component value and append it to the value of the block.
-            block->m_values.append(consume_a_component_value(tokens));
+            block_values.empend(consume_a_component_value(tokens));
         }
     }
 }

Userland/Libraries/LibWeb/CSS/StyleComputer.cpp

@@ -631,7 +631,7 @@ bool StyleComputer::expand_unresolved_values(DOM::Element& element, StringView p
             Vector<Parser::ComponentValue> block_values;
             if (!expand_unresolved_values(element, property_name, dependencies, source_block.values(), block_values, 0))
                 return false;
-            NonnullRefPtr<Parser::Block> block = adopt_ref(*new Parser::Block(source_block.token(), move(block_values)));
+            NonnullRefPtr<Parser::Block> block = Parser::Block::create(source_block.token(), move(block_values));
             dest.empend(move(block));
             continue;
         }