[Dashboard] Start using /list_tests's test_path_dict mode in test-picker

dashboard/dashboard/elements/test-picker-test.html

Index: dashboard/dashboard/elements/test-picker-test.html
diff --git a/dashboard/dashboard/elements/test-picker-test.html b/dashboard/dashboard/elements/test-picker-test.html
index 60596fb413c4703a5518ca7e4147c4d883abfd14..e663c116f6842d32a3eae6eac77763e3a5a1613e 100644
--- a/dashboard/dashboard/elements/test-picker-test.html
+++ b/dashboard/dashboard/elements/test-picker-test.html
@@ -146,5 +146,32 @@ tr.b.unittest.testSuite(function() {
     assert.deepEqual(benchmarkMenu.selectedItem.name, expectedBenchmark);
     assert.deepEqual(metricMenu.selectedItem.name, expectedMetric);
   }, testOptions);
+
+  test('getCurrentSelectionReturnsNullIfInvalid', function() {
+    testing_common.addXhrMock('*', JSON.stringify(MOCK_RESPONSE));
+    let testPicker = document.createElement('test-picker');
+    testPicker.testSuites = {
+      'endure': {
+        'mas': {'Chromium': {'mac': false, 'win7': true}},
+        'dep': true
+      },
+      'dromaeo': {
+        'mas': {'Chromium': {'mac': false, 'win7': false}}
+      },
+      'blink_perf': {
+        'mas': {'Chromium': {'mac': false, 'win7': false}},
+        'mon': ['select-multiple-add/select-multiple-add.html']
+      }
+    };
+
+    let suiteMenu = testPicker.getSelectionMenu(0);
+    suiteMenu.selectedItem = suiteMenu.items[0];
+
+    let botMenu = testPicker.getSelectionMenu(1);
+    botMenu.selectedItem = botMenu.items[0];
+
+    assert.isNull(testPicker.getCurrentSelection());
+    testing_common.clearXhrMock();
+  });
 });
 </script>