Remove parsing of %(branch) as it is not reliable from the buildbot waterfall.

scripts/master/factory/chromeos_factory.py

Index: scripts/master/factory/chromeos_factory.py
diff --git a/scripts/master/factory/chromeos_factory.py b/scripts/master/factory/chromeos_factory.py
index 5b753f5bb8c11f83eda3425df0f3e9e6df622ba4..e498294f7f3be956abb6f804c4a8a91faf9a4dbc 100644
--- a/scripts/master/factory/chromeos_factory.py
+++ b/scripts/master/factory/chromeos_factory.py
@@ -83,17 +83,11 @@ class CbuildbotFactory(object):
     clear_and_clone_cmd = 'rm -rf %s ; sleep 10 ;' % git_checkout_dir
     clear_and_clone_cmd += '%s clone %s;cd %s;' % (git_bin, repo,
                                                    git_checkout_dir)
-    # It's possible that branch can be coming from WithProperites set
-    # If the branch is master, then even if the branch is empty, it amounts
-    # to the same 'git checkout' or 'git checkout master'
-    # If self.branch is set to something otherthan master, that means, branch
-    # has been passed in and we want to honor the explicitly passed in branch
-    clear_and_clone_cmd += '%s checkout ' % git_bin
-    if self.branch == 'master':
-      clear_and_clone_cmd += '%(branch)s'
-    else:
-      clear_and_clone_cmd += self.branch
 
+    # We ignore branches coming from buildbot triggers and rely on those in the
+    # config.  This is because buildbot branch names do not match up with
+    # cros builds.
+    clear_and_clone_cmd += '%s checkout %s' % (git_bin, self.branch)
     msg = 'Clear and Clone %s' % git_checkout_dir
     if patch:
       clear_and_clone_cmd += ('; %s pull %s %s' %
@@ -101,7 +95,7 @@ class CbuildbotFactory(object):
       msg = 'Clear, Clone and Patch %s' % git_checkout_dir
 
     self.f_cbuild.addStep(shell.ShellCommand,
-                          command=WithProperties(clear_and_clone_cmd),
+                          command=clear_and_clone_cmd,
                           name=msg,
                           description=msg)