[depot_tools] Find, upload and apply patchset dependencies

third_party/upload.py

Index: third_party/upload.py
diff --git a/third_party/upload.py b/third_party/upload.py
index eac2a3d09928a16d0c740c5e6fd917094e054270..002a0d66a7d149e255f26fbeea33d43a78730f7e 100755
--- a/third_party/upload.py
+++ b/third_party/upload.py
@@ -635,6 +635,10 @@ group.add_option("--target_ref", action="store", dest="target_ref",
 parser.add_option("--cq_dry_run", action="store_true",
                   help="Send the patchset to do a CQ dry run right after "
                        "upload.")
+parser.add_option("--depends_on_patchset", action="store",
+                  dest="depends_on_patchset",
+                  help="The uploaded patchset this patchset depends on. The "
+                       "value will be in this format- issue_num:patchset_num")
 group.add_option("--download_base", action="store_true",
                  dest="download_base", default=False,
                  help="Base files will be downloaded by the server "
@@ -2436,6 +2440,8 @@ def RealMain(argv, data=None):
   if options.cq_dry_run:
     form_fields.append(("cq_dry_run", "1"))
     form_fields.append(("commit", "1"))
+  if options.depends_on_patchset:
+    form_fields.append(("depends_on_patchset", options.depends_on_patchset))
 
   # Process --message, --title and --file.
   message = options.message or ""