android_frameworks_base/data/fonts/system_fonts.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
    System Fonts

    This file lists the font families that will be used by default for all supported glyphs.
    Each entry consists of a family, various names that are supported by that family, and
    up to four font files. The font files are listed in the order of the styles which they
    support: regular, bold, italic and bold-italic. If less than four styles are listed, then
    the styles with no associated font file will be supported by the other font files listed.

    The first family is also the default font, which handles font request that have not specified
    specific font names.

    Any glyph that is not handled by the system fonts will cause a search of the fallback fonts.
    The default fallback fonts are specified in the file /system/etc/fallback_fonts.xml, and there
    is an optional file which may be supplied by vendors to specify other fallback fonts to use
    in /vendor/etc/fallback_fonts.xml.
-->
<familyset>

    <family>
        <nameset>
            <name>sans-serif</name>
            <name>arial</name>
            <name>helvetica</name>
            <name>tahoma</name>
            <name>verdana</name>
        </nameset>
        <fileset>
            <file>Roboto-Regular.ttf</file>
            <file>Roboto-Bold.ttf</file>
            <file>Roboto-Italic.ttf</file>
            <file>Roboto-BoldItalic.ttf</file>
        </fileset>
    </family>

    <family>
        <nameset>
            <name>sans-serif-light</name>
        </nameset>
        <fileset>
            <file>Roboto-Light.ttf</file>
            <file>Roboto-LightItalic.ttf</file>
        </fileset>
    </family>

    <family>
        <nameset>
            <name>sans-serif-thin</name>
        </nameset>
        <fileset>
            <file>Roboto-Thin.ttf</file>
            <file>Roboto-ThinItalic.ttf</file>
        </fileset>
    </family>

    <family>
        <nameset>
            <name>sans-serif-condensed</name>
        </nameset>
        <fileset>
            <file>RobotoCondensed-Regular.ttf</file>
            <file>RobotoCondensed-Bold.ttf</file>
            <file>RobotoCondensed-Italic.ttf</file>
            <file>RobotoCondensed-BoldItalic.ttf</file>
        </fileset>
    </family>
    <family>
        <nameset>
            <name>serif</name>
            <name>times</name>
            <name>times new roman</name>
            <name>palatino</name>
            <name>georgia</name>
            <name>baskerville</name>
            <name>goudy</name>
            <name>fantasy</name>
            <name>cursive</name>
            <name>ITC Stone Serif</name>
        </nameset>
        <fileset>
            <file>DroidSerif-Regular.ttf</file>
            <file>DroidSerif-Bold.ttf</file>
            <file>DroidSerif-Italic.ttf</file>
            <file>DroidSerif-BoldItalic.ttf</file>
        </fileset>
    </family>

    <family>
        <nameset>
            <name>Droid Sans</name>
        </nameset>
        <fileset>
            <file>DroidSans.ttf</file>
            <file>DroidSans-Bold.ttf</file>
        </fileset>
    </family>

    <family>
        <nameset>
            <name>monospace</name>
            <name>courier</name>
            <name>courier new</name>
            <name>monaco</name>
        </nameset>
        <fileset>
            <file>DroidSansMono.ttf</file>
        </fileset>
    </family>

</familyset>