bot: delay cleanup of temp test files in case we need to retry.

tools/testing/test_case.py

Index: tools/testing/test_case.py
diff --git a/tools/testing/test_case.py b/tools/testing/test_case.py
index 0f3c4458c8976b21705306f2c850d768998c9be0..5d3f8c226fa3b0556a9c5eb6e15a182856767281 100644
--- a/tools/testing/test_case.py
+++ b/tools/testing/test_case.py
@@ -119,7 +119,8 @@ class BrowserTestCase(StandardTestCase):
         return test_output
 
     command = self.run_arch.GetRunCommand()
-    test_output = self.RunCommand(command)
+    # Don't clean up just in case test turned out flaky and we want to retry.
+    test_output = self.RunCommand(command, cleanup=False)
     # The return value of DumpRenderedTree does not indicate test failing, but
     # the output does.
     if self.run_arch.HasFailed(test_output.output.stdout):
@@ -127,9 +128,10 @@ class BrowserTestCase(StandardTestCase):
       # DumpRenderTree is sometimes flaky in xvfb-run, try again in that case.
       if (self.run_arch.WasFlakyDrt(test_output.output.stderr)):
         print "\nFlaky Gtw-WARNING error found, trying again..."
-        test_output = self.RunCommand(command)
+        test_output = self.RunCommand(command, cleanup=False)
         if self.run_arch.HasFailed(test_output.output.stdout):
           test_output.output.exit_code = 1
+    self.Cleanup();
 
     return test_output