Bug fixed when:
* There are different texts.
* No font's family is set to the texts.
* Texts are not supported by the default font.
* Texts are set different sizes.
Only one default font (with only one size) was cached per script.
Change-Id: Ifdc1691b797432521c16f236769c127ab1848433 Signed-off-by: Victor Cebollada <v.cebollada@samsung.com>