Replace GetHostSize with a cross-platform implementation.

build/android/pylib/utils/host_utils.py

Index: build/android/pylib/utils/host_utils.py
diff --git a/build/android/pylib/utils/host_utils.py b/build/android/pylib/utils/host_utils.py
new file mode 100644
index 0000000000000000000000000000000000000000..580721f1275c5e19245c62676fb1ad114fc05aca
--- /dev/null
+++ b/build/android/pylib/utils/host_utils.py
@@ -0,0 +1,16 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+
+
+def GetRecursiveDiskUsage(path):
+  """Returns the disk usage in bytes of |path|. Similar to `du -sb |path|`."""
+  running_size = os.path.getsize(path)
+  if os.path.isdir(path):
+    for root, dirs, files in os.walk(path):
+      running_size += sum([os.path.getsize(os.path.join(root, f))
+                           for f in files + dirs])
+  return running_size
+