fix test broken issue when using --use-emulator

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 48e92ea3d6cec24f2d59731b4057a7c807c00b94..e3b6d87a3b3eef5b14803f4c96a6c7a2ba8ffb87 100644
--- a/build/android/pylib/single_test_runner.py
+++ b/build/android/pylib/single_test_runner.py
@@ -13,6 +13,11 @@ from test_package_apk import TestPackageApk
 from test_package_executable import TestPackageExecutable
 from test_result import TestResults
 
+# adb_interface.py is under ../../third_party/android_testrunner/
+sys.path.append(os.path.join(os.path.abspath(os.path.dirname(__file__)), '..',
+   '..', 'third_party', 'android_testrunner'))
+import run_command
+
 
 class SingleTestRunner(BaseTestRunner):
   """Single test suite attached to a single device.
@@ -292,6 +297,11 @@ class SingleTestRunner(BaseTestRunner):
   def SetUp(self):
     """Sets up necessary test enviroment for the test suite."""
     super(SingleTestRunner, self).SetUp()
+    # Sometimes adb server may crash and the connection to the device lost,
+    # which will block the test. So kill the server each time the test starts
+    # and the connection to the device will be re-established.
+    run_command.RunCommand('adb kill-server')

[John Grabowski, 2012/07/10 06:14:09]

prefer self.adb.SomethingOrOther() to a 'run command'.
I believe there is a KillServer() or RestartServer() function already.
If not, add one.

[Wei James(wistoch), 2012/07/10 14:26:48]

fixed. 

define Start/Kill/RestartAdbServer in adb_interface.py and use
RestartAdbServer() here. thanks 

+
     if self.test_package.performance_test:
       if run_tests_helper.IsRunningAsBuildbot():
         self.adb.SetJavaAssertsEnabled(enable=False)