Delay Class parsing until the class is actually used.

runtime/vm/parser.h

Index: runtime/vm/parser.h
===================================================================
--- runtime/vm/parser.h	(revision 22914)
+++ runtime/vm/parser.h	(working copy)
@@ -143,7 +143,7 @@
 
 class Parser : public ValueObject {
  public:
-  Parser(const Script& script, const Library& library);
+  Parser(const Script& script, const Library& library, intptr_t token_pos);
   Parser(const Script& script, ParsedFunction* function, intptr_t token_pos);
 
   // Parse the top level of a whole script file and register declared classes
@@ -151,6 +151,9 @@
   static void ParseCompilationUnit(const Library& library,
                                    const Script& script);
 
+  // Parse top level of a class and register all functions/fields.
+  static void ParseClass(const Class& cls);
+
   static void ParseFunction(ParsedFunction* parsed_function);
 
   // Format and print a message with source location.
@@ -270,6 +273,7 @@
   void SkipBlock();
   void SkipMetadata();
   void SkipToMatchingParenthesis();
+  void SkipToMatchingBraces();
   void SkipTypeArguments();
   void SkipType(bool allow_void);
   void SkipInitializers();
@@ -332,7 +336,8 @@
 
   // Support for parsing of scripts.
   void ParseTopLevel();
-  void ParseClassDefinition(const GrowableObjectArray& pending_classes);
+  void ParseClassDeclaration(const GrowableObjectArray& pending_classes);
+  void ParseClassDefinition(const Class& cls);
   void ParseMixinTypedef(const GrowableObjectArray& pending_classes);
   void ParseTypedef(const GrowableObjectArray& pending_classes);
   void ParseTopLevelVariable(TopLevel* top_level);