Default fetch to sso:// within cog

This CL makes fetch default to sso:// within the cog env. It also adds a helper within gclient_scm to check if the env is cog.

Bug: chrome-operations:170
Change-Id: I8c35348653406549fadbd08df3d9991bb24ca776
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3670721
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Reviewed-by: Joanna Wang <jojwang@chromium.org>
Commit-Queue: Aravind Vasudevan <aravindvasudev@google.com>

fetch.py

@@ -260,6 +260,11 @@ def run(options, spec, root):
   checkout_type = spec['type']
   checkout_spec = spec['%s_spec' % checkout_type]
 
+  # Use sso:// by default if the env is cog
+  if not options.protocol_override and \
+    os.getcwd().startswith('/google/src/cloud'):
+    options.protocol_override = 'sso'
+
   # Replace https using the protocol specified in --protocol-override
   if options.protocol_override is not None:
     for solution in checkout_spec['solutions']:

gclient_scm.py

@@ -208,6 +208,16 @@ class GitWrapper(SCMWrapper):
   name = 'git'
   remote = 'origin'
 
+  _is_env_cog = None
+
+  @staticmethod
+  def _IsCog():
+    """Returns true if the env is cog"""
+    if not GitWrapper._is_env_cog:
+      GitWrapper._is_env_cog = os.getcwd().startswith('/google/src/cloud')
+
+    return GitWrapper._is_env_cog
+
   @property
   def cache_dir(self):
     try: