Add a new 'format-webkitpy' command that will reformat code to the style guide.

Tools/Scripts/webkitpy/formatter/fix_double_quote_strings.py

Index: Tools/Scripts/webkitpy/formatter/fix_double_quote_strings.py
diff --git a/Tools/Scripts/webkitpy/formatter/fix_double_quote_strings.py b/Tools/Scripts/webkitpy/formatter/fix_double_quote_strings.py
new file mode 100644
index 0000000000000000000000000000000000000000..45f988d5ad9fa31468a20c412d211b8affdaa6e2
--- /dev/null
+++ b/Tools/Scripts/webkitpy/formatter/fix_double_quote_strings.py
@@ -0,0 +1,29 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+A 2to3 fixer that converts all string literals to use double quotes.
+
+Strings that contain double quotes will not be modified. Prefixed string
+literals will also not be modified. This affects both single-quoted strings
+and triple-single-quoted strings.
+
+"""
+
+from lib2to3.fixer_base import BaseFix
+from lib2to3.pgen2 import token
+
+
+class FixDoubleQuoteStrings(BaseFix):
+
+    explicit = True
+    _accept_type = token.STRING
+
+    def match(self, node):
+        res = node.value.startswith("'") and '"' not in node.value[1:-1]
+        return res
+
+    def transform(self, node, results):
+        node.value = node.value.replace("'", '"')
+        node.changed()