Add support for building the Dart VM for Android OS.

utils/compiler/compiler.gyp

Index: utils/compiler/compiler.gyp
diff --git a/utils/compiler/compiler.gyp b/utils/compiler/compiler.gyp
index d419a5f5d912dbefbe0990e29f0d7aa3108d92d4..8555de1fc30a53690ff351ab171a70ecd86b935b 100644
--- a/utils/compiler/compiler.gyp
+++ b/utils/compiler/compiler.gyp
@@ -12,8 +12,16 @@
       'type': 'none',
       'dependencies': [
         '../../runtime/dart-runtime.gyp:dart',
-        '../../third_party/v8/src/d8.gyp:d8',
       ],
+      'conditions': [
+        ['dart_want_separate_host_toolset!=1', {
+          'dependencies': [
+            '../../third_party/v8/src/d8.gyp:d8',
+            ]
+          }
+        ]
+      ],
+
       'actions': [
         {
           'action_name': 'build_dart2js',
@@ -46,6 +54,13 @@
           ],
         },
       ],
+      'conditions': [
+          ['dart_want_separate_host_toolset==1', {
+            'toolsets': ['host'],
+          }, {
+            'toolsets': ['target'],
+          }]
+      ],
     },
   ],
 }