Do not assume gclient is in the PATH.

apply_issue.py

Index: apply_issue.py
diff --git a/apply_issue.py b/apply_issue.py
index 3b3f1f4c1db22907a1b082cb293cce875c33000e..8b50b37e50a53b76c5328e92512e7d4463dd43c8 100755
--- a/apply_issue.py
+++ b/apply_issue.py
@@ -22,6 +22,8 @@ import gclient_utils
 import rietveld
 import scm
 
+BASE_DIR = os.path.dirname(os.path.abspath(__file__))
+
 
 def main():
   parser = optparse.OptionParser(description=sys.modules[__name__].__doc__)
@@ -119,8 +121,11 @@ def main():
           'A DEPS file was updated inside a gclient checkout, running gclient '
           'sync.')
       base_rev = 'BASE' if scm_type == 'svn' else 'HEAD'
+      gclient_path = os.path.join(BASE_DIR, 'gclient')
+      if sys.platform == 'win32':
+        gclient_path += '.bat'
       return subprocess.call(
-          ['gclient', 'sync', '--revision', base_rev], cwd=gclient_root)
+          [gclient_path, 'sync', '--revision', base_rev], cwd=gclient_root)
   return 0