scm.SVN.GenerateDiff() expects an array.

So pass a single item array. The presubmit checks would fail otherwise.

This code path was definitely not exercised by the unit tests. Unit tests are
left as an exercise to the reader.

TBR=vbendeb
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6479006

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@74396 0039d316-1c4b-4281-b951-d872f2087c98

presubmit_support.py

@@ -558,7 +558,8 @@ class SvnAffectedFile(AffectedFile):
     return self._is_text_file
 
   def GenerateScmDiff(self):
-    return scm.SVN.GenerateDiff(self.AbsoluteLocalPath())
+    return scm.SVN.GenerateDiff([self.AbsoluteLocalPath()])
+
 
 class GitAffectedFile(AffectedFile):
   """Representation of a file in a change out of a git checkout."""