fixed uninit error in chromedriver unittests Device::ForwardDevtoolsPort

chrome/test/chromedriver/chrome/device_manager_unittest.cc

Index: chrome/test/chromedriver/chrome/device_manager_unittest.cc
diff --git a/chrome/test/chromedriver/chrome/device_manager_unittest.cc b/chrome/test/chromedriver/chrome/device_manager_unittest.cc
index cb12f010e1be267268c2b7fa9ef460d9376bf896..05e789bae37370c94d8a70f85167f721060c64b9 100644
--- a/chrome/test/chromedriver/chrome/device_manager_unittest.cc
+++ b/chrome/test/chromedriver/chrome/device_manager_unittest.cc
@@ -67,6 +67,7 @@ class FakeAdb : public Adb {
   virtual Status GetPidByName(const std::string& device_serial,
                               const std::string& process_name,
                               int* pid) OVERRIDE {
+    *pid = 0; // avoid uninit error crbug.com/393231
     return Status(kOk);
   }
 };