Add fetch hook for ANGLE.

Bug: angleproject:7018
Change-Id: I0e685c81a43d247b4f1a0dd93850b30b829ef264
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3461421
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/fetch.py b/fetch.py
index 74b2298..2b7245d 100755
--- a/fetch.py
+++ b/fetch.py
@@ -93,7 +93,7 @@
     try:
       gclient_root = self.run_gclient('root', return_stdout=True).strip()
       return (os.path.exists(os.path.join(gclient_root, '.gclient')) or
-              os.path.exists(os.path.join(os.getcwd(), self.root)))
+              os.path.exists(os.path.join(os.getcwd(), self.root, '.git')))
     except subprocess.CalledProcessError:
       pass
     return os.path.exists(os.path.join(os.getcwd(), self.root))