rebaseline-cl: Add logic for selecting a related builder when filling in results.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.py b/third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.py
index 7a205dd6d3467b7eb85d8040fadd7f5f945fd24a..fd7f554d8e1d5eee9c7ec8ed4187b5ff69bdacb9 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.py
@@ -357,3 +357,44 @@ class RebaselineCLTest(BaseTestCase, LoggingTestCase):
             'INFO: For fast/dom/prototype-taco.html:\n',
             'INFO: Using Build(builder_name=\'MOCK Try Linux\', build_number=100) to supply results for test-mac-mac10.11.\n',
         ])
+
+    def test_fill_in_missing_results_prefers_build_with_same_os_type(self):
+        self.tool.builders = BuilderList({
+            'MOCK Foo12': {
+                'port_name': 'foo-foo12',
+                'specifiers': ['Foo12', 'Release'],
+                'is_try_builder': True,
+            },
+            'MOCK Foo45': {
+                'port_name': 'foo-foo45',
+                'specifiers': ['Foo45', 'Release'],
+                'is_try_builder': True,
+            },
+            'MOCK Bar3': {
+                'port_name': 'bar-bar3',
+                'specifiers': ['Bar3', 'Release'],
+                'is_try_builder': True,
+            },
+            'MOCK Bar4': {
+                'port_name': 'bar-bar4',
+                'specifiers': ['Bar4', 'Release'],
+                'is_try_builder': True,
+            },
+        })
+        test_baseline_set = TestBaselineSet(self.tool)
+        test_baseline_set.add('fast/dom/prototype-taco.html', Build('MOCK Foo12', 100))
+        test_baseline_set.add('fast/dom/prototype-taco.html', Build('MOCK Bar4', 200))
+        self.command.fill_in_missing_results(test_baseline_set)
+        self.assertEqual(
+            test_baseline_set.build_port_pairs('fast/dom/prototype-taco.html'),
+            [
+                (Build(builder_name='MOCK Foo12', build_number=100), 'foo-foo12'),
+                (Build(builder_name='MOCK Bar4', build_number=200), 'bar-bar4'),
+                (Build(builder_name='MOCK Foo12', build_number=100), 'foo-foo45'),
+                (Build(builder_name='MOCK Bar4', build_number=200), 'bar-bar3'),
+            ])
+        self.assertLog([
+            'INFO: For fast/dom/prototype-taco.html:\n',
+            'INFO: Using Build(builder_name=\'MOCK Foo12\', build_number=100) to supply results for foo-foo45.\n',
+            'INFO: Using Build(builder_name=\'MOCK Bar4\', build_number=200) to supply results for bar-bar3.\n',
+        ])