Make build_utils.ZipDir() work on Windows.

Bug: 870611
Change-Id: I311f2dcdafe25fea71ce0494424602e0e1989bb7
Reviewed-on: https://chromium-review.googlesource.com/c/1298174Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602415}

build/android/gyp/util/build_utils.py

@@ -322,7 +322,7 @@ def AddToZipHermetic(zip_file, zip_path, src_path=None, data=None,
     return
 
   if src_path:
-    with file(src_path) as f:
+    with open(src_path, 'rb') as f:
       data = f.read()
 
   # zipfile will deflate even when it makes the file bigger. To avoid