Add support for conditions on DEPS file.

See https://chromium-review.googlesource.com/687499 for the corresponding Chromium change.

Bug: None
Change-Id: I23330d161dc60fd4c8681e58ce5a8e20a2b4a3b8
Reviewed-on: https://webrtc-review.googlesource.com/4540
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Commit-Queue: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20032}

tools_webrtc/autoroller/roll_deps.py

@@ -210,10 +210,8 @@ def BuildDepsentryDict(deps_dict):
   def AddDepsEntries(deps_subdict):
     for path, deps_url in deps_subdict.iteritems():
       if isinstance(deps_url, dict):
-        # We don't support deps conditional on a variable.
-        # This is needed after http://crrev.com/9f8b8eb2
-        continue
-      elif not result.has_key(path):
+        deps_url = deps_url['url']
+      if not result.has_key(path):
         url, revision = deps_url.split('@') if deps_url else (None, None)
         result[path] = DepsEntry(path, url, revision)