Fix crash when the service cannot start.

SpeechSynthesizerService::speech_synthesizer_ should be released by g_object_unref, not by delete

BUG=chromium-os:22031
TEST=No crash even when audio device is not available.

Change-Id: I2155aeb804c2eb2695494cbf53c745f9bed8e61a
Reviewed-on: https://gerrit.chromium.org/gerrit/10839
Reviewed-by: Dominic Mazzoni <[email protected]>
Tested-by: Ryo Hashimoto <[email protected]>
2 files changed