tools/valgrind: Add function for ui_base_unittests target variant.

tools/valgrind/chrome_tests.py

Index: tools/valgrind/chrome_tests.py
diff --git a/tools/valgrind/chrome_tests.py b/tools/valgrind/chrome_tests.py
index d5f3d18540e0811681d16c74b57147050afdcd39..9b0b52fa12e0f12e3d9672b6cb0043dffb9c8814 100755
--- a/tools/valgrind/chrome_tests.py
+++ b/tools/valgrind/chrome_tests.py
@@ -475,6 +475,9 @@ class ChromeTests:
       return 0;
     return self.SimpleTest("chrome", "unit_tests")
 
+  def TestUIBaseUnit(self):
+    return self.SimpleTest("chrome", "ui_base_unittests")
+
   def TestUIUnit(self):
     return self.SimpleTest("chrome", "ui_unittests")
 
@@ -723,6 +726,7 @@ class ChromeTests:
     "sync": TestSync,            "sync_unit_tests": TestSync,
     "sync_integration_tests": TestSyncIntegration,
     "sync_integration": TestSyncIntegration,
+    "ui_base_unit": TestUIBaseUnit,       "ui_base_unittests": TestUIBaseUnit,
     "ui_unit": TestUIUnit,       "ui_unittests": TestUIUnit,
     "unit": TestUnit,            "unit_tests": TestUnit,
     "url": TestURL,              "url_unittests": TestURL,