Remove most superfluous getter arguments from dart2js.

dart/lib/compiler/implementation/lib/io.dart

Index: dart/lib/compiler/implementation/lib/io.dart
diff --git a/dart/lib/compiler/implementation/lib/io.dart b/dart/lib/compiler/implementation/lib/io.dart
index 4cd7cecd8da9cc56d0435b7285b66859627fb10d..7d412c2213405d996cc3a73c1ad0b2ec1a733109 100644
--- a/dart/lib/compiler/implementation/lib/io.dart
+++ b/dart/lib/compiler/implementation/lib/io.dart
@@ -76,23 +76,23 @@ class _File {
 }
 
 class _Platform {
-  static int get numberOfProcessors() {
+  static int get numberOfProcessors {
     throw new UnsupportedOperationException('_Platform.numberOfProcessors');
   }
 
-  static String get pathSeparator() {
+  static String get pathSeparator {
     throw new UnsupportedOperationException('_Platform.pathSeparator');
   }
 
-  static String get operatingSystem() {
+  static String get operatingSystem {
     throw new UnsupportedOperationException('_Platform.operatingSystem');
   }
 
-  static String get localHostname() {
+  static String get localHostname {
     throw new UnsupportedOperationException('_Platform.localHostname');
   }
 
-  static Map<String, String> get environment() {
+  static Map<String, String> get environment {
     throw new UnsupportedOperationException('_Platform.environment');
   }
 }
@@ -157,7 +157,7 @@ class _EventHandler {
     throw new UnsupportedOperationException(msg);
   }
 
-  static _EventHandler get _eventHandler() {
+  static _EventHandler get _eventHandler {
     throw new UnsupportedOperationException('_EventHandler._eventhandler');
   }