Dont allocate GCond in VideoSinkGStreamer.cpp dynamically.

Dont allocate GCond in VideoSinkGStreamer.cpp dynamically.

Rubber-stamped by Carlos Garcia Campos.

* platform/graphics/gstreamer/VideoSinkGStreamer.cpp:
(_WebKitVideoSinkPrivate::_WebKitVideoSinkPrivate): Move the
g_cond_init() and gst_video_info_init() calls here.
(_WebKitVideoSinkPrivate::~_WebKitVideoSinkPrivate): Move the
g_cond_clear() call here.
(webkit_video_sink_init):
(webkitVideoSinkTimeoutCallback):
(webkitVideoSinkRender):
(unlockBufferMutex):
(webkit_video_sink_class_init):
(webkitVideoSinkDispose): Deleted. Not required anymore.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@172443 268f45cc-cd09-0410-ab3c-d52691b4dbfc