Added allowed_hosts to DEPS.

DEPS

Index: DEPS
diff --git a/DEPS b/DEPS
index 6d4ba06e77c709d2f036a519c56ae426f2c7c5fc..f047c70acb8549e9fcd8b31b6251005ad44d3ab3 100644
--- a/DEPS
+++ b/DEPS
@@ -90,6 +90,14 @@ vars = {
   'nacl_revision': 'd4f6ba5e0cd805c6f8085f5f69d06a5e17341d16', # from svn revision r13748
 }
 
+# Only these hosts are allowed for dependencies in this DEPS file.
+# If you need to add a new host, contact chrome infrastracture team.
+allowed_hosts = [
+  'chromium.googlesource.com',
+  'boringssl.googlesource.com',
+  'pdfium.googlesource.com',
+]
+
 deps = {
   'src/breakpad/src':
    Var('chromium_git') + '/external/google-breakpad/src.git' + '@' + '9b7051fd52f7377dc08e88133e3c0d3da5f105c3', # from svn revision 1375