Fix infinite loop in grit headers clobbering script.

It turns out that on Windows the path-splitting function will always preserve the drive part (c:\).

TEST=none
http://crbug.com/17706

Review URL: http://codereview.chromium.org/159827

git-svn-id: http://src.chromium.org/svn/trunk/src/build@22344 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

win/clobber_generated_headers.py

@@ -22,6 +22,8 @@ def total_split(path):
   components = []
   while path:
     head, tail = os.path.split(path)
+    if not tail:
+      break
     components.append(tail)
     path = head
   return list(reversed(components))
@@ -46,4 +48,4 @@ for path in sys.argv[1:]:
         os.remove(full_path)
         print 'Clobbered ' + full_path
       except OSError:
-        print 'Could not remove ' + full_path + '. Continuing.'
+        print 'Could not remove ' + full_path + '. Continuing.'