Fix the corner case issue with Android test sharder.

Previously all gtests would run if the shard list was empty.

BUG=165529

Review URL: https://codereview.chromium.org/11557004

git-svn-id: http://src.chromium.org/svn/trunk/src/build@172630 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

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:
-          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

android/pylib/test_package.py

@@ -91,6 +91,22 @@ class TestPackage(object):
     return ['DISABLED_', 'FLAKY_', 'FAILS_']
 
   def _ParseGTestListTests(self, all_tests):
+    """Parses and filters the raw test lists.
+
+    Args:
+    all_tests: The raw test listing with the following format:
+
+      IPCChannelTest.
+        SendMessageInChannelConnected
+      IPCSyncChannelTest.
+        Simple
+        DISABLED_SendWithTimeoutMixedOKAndTimeout
+
+    Returns:
+      A list of non-disabled tests. For the above raw listing:
+
+      [IPCChannelTest.SendMessageInChannelConnected, IPCSyncChannelTest.Simple]
+    """
     ret = []
     current = ''
     disabled_prefixes = self.GetDisabledPrefixes()