Add a dedicated pretty-diff command.

This will let us delete webkit-patch and a bunch of
python code and it will save me some annoyance at
needing to type "webkit-patch pretty-diff" all
the time.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/944193003

engine/src/flutter/tools/pretty-diff

@@ -0,0 +1,96 @@
+#!/usr/bin/env python
+# Copyright (c) 2011 Code Aurora Forum. All rights reserved.
+# Copyright (c) 2010 Google Inc. All rights reserved.
+# Copyright (c) 2009 Apple Inc. All rights reserved.
+# Copyright (C) 2010 Chris Jerdonek (cjerdonek@webkit.org)
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# A tool for automating dealing with bugzilla, posting patches, committing patches, etc.
+
+import time
+import urllib
+import webbrowser
+
+from webkitpy.common.prettypatch import PrettyPatch
+from webkitpy.common.system import logutils
+from webkitpy.common.system.executive import Executive
+from webkitpy.common.system.executive import ScriptError
+from webkitpy.common.system.filesystem import FileSystem
+from webkitpy.common.checkout.scm.detection import detect_scm_system
+
+
+_log = logutils.get_logger(__file__)
+
+
+def can_open_url():
+    try:
+        webbrowser.get()
+        return True
+    except webbrowser.Error, e:
+        return False
+
+def open_url(url):
+    if not can_open_url():
+        _log.warn("Failed to open %s" % url)
+    webbrowser.open(url)
+
+def show_pretty_diff():
+    if not can_open_url():
+        return None
+
+    try:
+        pretty_patch = PrettyPatch(Executive())
+        pretty_diff_file = pretty_patch.pretty_diff_file(diff())
+        url = "file://%s" % urllib.quote(pretty_diff_file.name)
+        open_url(url)
+        # We return the pretty_diff_file here because we need to keep the
+        # file alive until the user has had a chance to confirm the diff.
+        return pretty_diff_file
+    except ScriptError, e:
+        _log.warning("PrettyPatch failed.  :(")
+    except OSError, e:
+        _log.warning("PrettyPatch unavailable.")
+
+def diff():
+    scm = detect_scm_system(FileSystem().getcwd())
+    changed_files = scm.changed_files()
+    return scm.create_patch(None, changed_files=changed_files)
+
+def main():
+    pretty_diff_file = show_pretty_diff()
+    # This is a terrible hack. Try to give enough time for the
+    # browser to actually load the file.
+    time.sleep(1)
+    if pretty_diff_file:
+        pretty_diff_file.close()
+
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        sys.exit(signal.SIGINT + 128)