Make dart2js work on Windows.

dart/utils/compiler/compiler.gyp

Index: dart/utils/compiler/compiler.gyp
diff --git a/dart/utils/compiler/compiler.gyp b/dart/utils/compiler/compiler.gyp
index ecccdaf9cd57873e38b226a97f948a50993adff7..0eb0eb3967f75321c0ac422023e42f9bd460a9a0 100644
--- a/dart/utils/compiler/compiler.gyp
+++ b/dart/utils/compiler/compiler.gyp
@@ -3,6 +3,9 @@
 # BSD-style license that can be found in the LICENSE file.
 
 {
+  'variables': {
+    'dart_dir': '../..',
+  },
   'targets': [
     {
       'target_name': 'dart2js',
@@ -14,7 +17,7 @@
         {
           'action_name': 'build_dart2js',
           'inputs': [
-            '<(PRODUCT_DIR)/dart',
+            '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
             'build_helper.dart',
           ],
           'outputs': [
@@ -22,12 +25,18 @@
             '<(PRODUCT_DIR)/dart2js_developer',
           ],
           'action': [
-            '<(PRODUCT_DIR)/dart',
+            '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
+            '--enable-checked-mode',
             'build_helper.dart',
+            # Note: it would seem more straight-forward to pass in
+            # '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)'.
+            # Unfortunately, there is some strange interaction with
+            # GYP so it doesn't work.
             '<(PRODUCT_DIR)',
-            'dart',
+            '<(EXECUTABLE_PREFIX)dart<(EXECUTABLE_SUFFIX)',
             'dart2js',
             'dart2js_developer',
+            '<(dart_dir)',
           ],
         },
       ],