Fix most warnings and other minor cleanups.

lib/compiler/implementation/native_handler.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library('native');
 #import('dart:uri');
 #import('leg.dart');
 #import('elements/elements.dart');
 #import('scanner/scannerlib.dart');
 #import('ssa/ssa.dart');
@@ skipping 200 matching lines @@
       && nativeEmitter.toNativeName(element.enclosingElement) == 'DOMType') {
     Element methodElement =
         compiler.findHelper(const SourceString('getTypeNameOf'));
     HStatic method = new HStatic(methodElement);
     builder.add(method);
     builder.push(new HInvokeStatic(Selector.INVOCATION_1,
         <HInstruction>[method, builder.localsHandler.readThis()]));
     return;
   }
 
-  HInstruction convertDartClosure(Element parameter, Type type) {
+  HInstruction convertDartClosure(Element parameter, FunctionType type) {
     HInstruction local = builder.localsHandler.readLocal(parameter);
     // TODO(ngeoffray): For static methods, we could pass a method with a
     // defined arity.
     builder.push(new HStatic(builder.interceptors.getClosureConverter()));
     HInstruction arity = builder.graph.addConstantInt(type.computeArity());
     List<HInstruction> callInputs = <HInstruction>[builder.pop(), local, arity];
     HInstruction closure = new HInvokeStatic(Selector.INVOCATION_1, callInputs);
     builder.add(closure);
     return closure;
   }
@@ skipping 121 matching lines @@
                                       String parameters) {
   buffer.add("  if (Object.getPrototypeOf(this).hasOwnProperty");
   buffer.add("('$methodName')) {\n");
   buffer.add("  $code");
   buffer.add("  } else {\n");
   buffer.add("    return Object.prototype.$methodName.call(this");
   buffer.add(parameters == '' ? '' : ', $parameters');
   buffer.add(");\n");
   buffer.add("  }\n");
 }