Fix the corner case issue with Android test sharder.

build/android/pylib/single_test_runner.py

Index: build/android/pylib/single_test_runner.py
diff --git a/build/android/pylib/single_test_runner.py b/build/android/pylib/single_test_runner.py
index 8a450c287990a9e07a684094831ffed8c2e79690..85e0ab7c5dfde2395bf6674e9728d024c25f6b28 100644
--- a/build/android/pylib/single_test_runner.py
+++ b/build/android/pylib/single_test_runner.py
@@ -329,10 +329,6 @@ class SingleTestRunner(BaseTestRunner):
       if self.test_package.rebaseline:
         self.RebaselineTests()
       else:
-        if not self._gtest_filter:

[bulach, 2012/12/12 11:38:59]

yeah, I think this was done before we unified the sharder: it was possible to
hit here without a "-f" param, and so we'd run all the non-disabled tests..
now that we always go through sharding, even with one device, we always have the
filter set here.

btw, if you're willing to cleanup: the rebaseline option was done so when we
merged, we'd re-generate the foo_disabled_tests at once...

this is now truly obsolete, there's no scenario in which we'd regenerate that
file.. this "rebaseline" option pollutes and traverses a lot of layers, feel
free to clean up when you have a moment! 

-          self._gtest_filter = ('-' + ':'.join(self.GetDisabledTests()) + ':' +
-                               ':'.join(['*.' + x + '*' for x in
-                                 self.test_package.GetDisabledPrefixes()]))
         self.RunTestsWithFilter()
     except errors.DeviceUnresponsiveError as e:
       # Make sure this device is not attached