[git_cache] support ssh url

Paths containing ':' characters are illegal only on Windows platforms.
So, ssh_url like git@github.com:chromium/chromium.git will generate
runtime exception on Windows. We replace ':' with '__' to avoid
exceptions in the ssh form of git_url case.

R=ddoman@chromium.org

Bug: 329781388

Change-Id: Ia4db6a0927b40b521477e5d90addb4056c2c8ef8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5369296
Auto-Submit: 吴金立 <wujinli.cn@gmail.com>
Reviewed-by: Aravind Vasudevan <aravindvasudev@google.com>
Commit-Queue: Joanna Wang <jojwang@chromium.org>

git_cache.py

@@ -176,6 +176,8 @@ class Mirror(object):
         # Use the same dir for authenticated URLs and unauthenticated URLs.
         norm_url = norm_url.replace('googlesource.com/a/', 'googlesource.com/')
 
+        norm_url = norm_url.replace(':', '__')
+
         return norm_url.replace('-', '--').replace('/', '-').lower()
 
     @staticmethod
@@ -183,6 +185,12 @@ class Mirror(object):
         """Convert a cache dir path to its corresponding url."""
         netpath = re.sub(r'\b-\b', '/',
                          os.path.basename(path)).replace('--', '-')
+
+        netpath = netpath.replace('__', ':')
+
+        if netpath.startswith('git@'):
+            return netpath
+
         return 'https://%s' % netpath
 
     @classmethod