For this You want to Use Opera Mini version On your Mobile...
01. Type "Opera:config" on your opera mini address bar and go..
02. Power user setting will appear on your browser.
.
03. Scroll down the page and Last one is "Use bitmap fonts for complex scripts"
Make that One "No" to "Yes" -----> Save the page...
04. Enjoy Sinhala Font on your Mobile....
Just Simple.....
