Add constructors for Float32Array and friends.

client/html/src/Float64Array.dart

Index: client/html/src/Float64Array.dart
diff --git a/client/html/src/Float64Array.dart b/client/html/src/Float64Array.dart
new file mode 100644
index 0000000000000000000000000000000000000000..b1c0543106692cf210345af2c90377fa0535fae6
--- /dev/null
+++ b/client/html/src/Float64Array.dart
@@ -0,0 +1,19 @@
+// Copyright (c) 2011, 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 fil default-styleWrappingImplementatione.
+
+interface Float64Array extends ArrayBufferView
+    default Float64ArrayWrappingImplementation {
+
+  static final int BYTES_PER_ELEMENT = 8;
+
+  Float64Array(int length);
+
+  Float64Array.from(List<num> list);
+
+  Float64Array.fromBuffer(ArrayBuffer buffer);
+
+  int get length();
+
+  Float64Array subarray(int start, [int end]);
+}