Move DBusClient stub implementations into separate files.

chromeos/network/network_sms_handler_unittest.cc

Index: chromeos/network/network_sms_handler_unittest.cc
diff --git a/chromeos/network/network_sms_handler_unittest.cc b/chromeos/network/network_sms_handler_unittest.cc
index c3d434b767a4324baee36eacec33203b08ab2172..9c9d6b83bd136582fa915db735b7a02e6ab3d7a5 100644
--- a/chromeos/network/network_sms_handler_unittest.cc
+++ b/chromeos/network/network_sms_handler_unittest.cc
@@ -103,7 +103,7 @@ TEST_F(NetworkSmsHandlerTest, SmsHandlerDbusStub) {
   // Note: The following string corresponds to values in
   // ModemMessagingClientStubImpl and SmsClientStubImpl.
   // TODO(stevenjb): Use a TestInterface to set this up to remove dependency.
-  const char kMessage1[] = "SMSClientStubImpl: Test Message: /SMS/0";
+  const char kMessage1[] = "FakeSMSClient: Test Message: /SMS/0";
   EXPECT_EQ(messages.find(kMessage1), messages.end());
 
   // Test for messages delivered by signals.