Fix remaining warnings.

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 186 matching lines @@
   element.setNative();
   NativeEmitter nativeEmitter = compiler.emitter.nativeEmitter;
   // If what we're compiling is a getter named 'typeName' and the native
   // class is named 'DOMType', we generate a call to the typeNameOf
   // function attached on the isolate.
   // The DOM classes assume that their 'typeName' property, which is
   // not a JS property on the DOM types, returns the type name.
   if (element.name == const SourceString('typeName')
       && element.isGetter()
       && nativeEmitter.toNativeName(element.enclosingElement) == 'DOMType') {
-    Element element = compiler.findHelper(const SourceString('getTypeNameOf'));
-    HStatic method = new HStatic(element);
+    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) {
     HInstruction local = builder.localsHandler.readLocal(parameter);
     // TODO(ngeoffray): by better analyzing the function type and
     // its formal parameters, we could pass a method with a defined arity.
@@ skipping 86 matching lines @@
 }
 
 void generateMethodWithPrototypeCheckForElement(Compiler compiler,
                                                 StringBuffer buffer,
                                                 FunctionElement element,
                                                 String code,
                                                 String parameters) {
   String methodName;
   Namer namer = compiler.namer;
   if (element.kind == ElementKind.FUNCTION) {
-    FunctionParameters parameters = element.computeParameters(compiler);
+    FunctionParameters computedParameters =
+        element.computeParameters(compiler);
     methodName = namer.instanceMethodName(
-        element.getLibrary(), element.name, parameters.parameterCount);
+        element.getLibrary(), element.name, computedParameters.parameterCount);
   } else if (element.kind == ElementKind.GETTER) {
     methodName = namer.getterName(element.getLibrary(), element.name);
   } else if (element.kind == ElementKind.SETTER) {
     methodName = namer.setterName(element.getLibrary(), element.name);
   } else {
     compiler.internalError('unexpected kind: "${element.kind}"',
                            element: element);
   }
 
   generateMethodWithPrototypeCheck(
@@ skipping 13 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");
 }