perf-o-matic should store chromium svn revision

perf-o-matic should store chromium svn revision
https://bugs.webkit.org/show_bug.cgi?id=77725

Reviewed by Dirk Pranke.

.:

Store both WebKit and Chromium revisions when both are reported.

* Websites/webkit-perf.appspot.com/models.py:
(Build):
* Websites/webkit-perf.appspot.com/report_handler.py:
(ReportHandler.post):
(ReportHandler._create_build_if_possible):
(ReportHandler._create_build_if_possible.execute):
* Websites/webkit-perf.appspot.com/static/manual-submit.html:

Tools:

Report both WebKit and Chromium revisions to the graph server. Renamed test_repository_paths to
repository_paths since it's nothing to do with tests. Also refactored scm so that head_svn_revision
is implemented in terms of newly added svn_revision.

* Scripts/webkitpy/common/checkout/scm/git.py:
(Git.svn_revision):
* Scripts/webkitpy/common/checkout/scm/scm.py:
(SCM.head_svn_revision):
(SCM):
(SCM.svn_revision):
* Scripts/webkitpy/common/checkout/scm/scm_mock.py:
(MockSCM.svn_revision):
* Scripts/webkitpy/common/checkout/scm/svn.py:
(SVN.svn_revision):
* Scripts/webkitpy/layout_tests/layout_package/json_layout_results_generator.py:
(JSONLayoutResultsGenerator.__init__):
* Scripts/webkitpy/layout_tests/layout_package/json_results_generator.py:
(JSONResultsGeneratorBase._insert_generic_metadata):
* Scripts/webkitpy/layout_tests/port/base.py:
(Port.repository_paths):
* Scripts/webkitpy/layout_tests/port/chromium.py:
(ChromiumPort.repository_paths):
* Scripts/webkitpy/performance_tests/perftestsrunner.py:
(PerfTestsRunner._generate_json):
* Scripts/webkitpy/performance_tests/perftestsrunner_unittest.py:
(test_run_test_set_with_json_output):
(test_run_test_set_with_json_source):
(test_run_test_set_with_multiple_repositories):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@106687 268f45cc-cd09-0410-ab3c-d52691b4dbfc