git-cl: Report git push information to metrics collection.

Bug: 897394
Change-Id: I52a31bb4840b5de89b96545a3e7544c6708f148f
Reviewed-on: https://chromium-review.googlesource.com/c/1312240
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

metrics_utils.py

@@ -142,6 +142,23 @@ GIT_VERSION_RE = re.compile(
   r'git version (\d)\.(\d{0,2})\.(\d{0,2})'
 )
 
+KNOWN_SUBCOMMAND_ARGS = {
+  'cc',
+  'hashtag',
+  'l=Auto-Submit+1',
+  'l=Commit-Queue+1',
+  'l=Commit-Queue+2',
+  'label',
+  'm',
+  'notify=ALL',
+  'notify=NONE',
+  'private',
+  'r',
+  'ready',
+  'topic',
+  'wip'
+}
+
 
 def get_python_version():
   """Return the python version in the major.minor.micro format."""
@@ -178,6 +195,19 @@ def seconds_to_weeks(duration):
   return int(duration) >> 19
 
 
+def extract_known_subcommand_args(args):
+  """Extract the known arguments from the passed list of args."""
+  known_args = []
+  for arg in args:
+    if arg in KNOWN_SUBCOMMAND_ARGS:
+      known_args.append(arg)
+    else:
+      arg = arg.split('=')[0]
+      if arg in KNOWN_SUBCOMMAND_ARGS:
+        known_args.append(arg)
+  return known_args
+
+
 def extract_http_metrics(request_uri, method, status, response_time):
   """Extract metrics from the request URI.