I have found the xml file that has to be changed to show the comskip markers.
It's "common.progressbar.xml".
In Titan skin where comskip markers are working it's "VideoOSD.xml".
By comparing these two files I have changed the "common.progressbar.xml" for support of Comskip markers in StreamedMP skin.
Now it's working on my side. But now the start position and the end position of the progress bar are not at the same point as before. Further the orange progress bar that shows the comskip markers is a little bit thicker than the blue progress bar.
Attached the png files that I'm using.
not working common.progressbar.xml
<control>
<description>Progress Bar</description>
<type>progress</type>
<id>1</id>
<posX>288</posX>
<posY>1018</posY>
<width>1358</width>
<label>#percentage</label>
<texturebg>-</texturebg>
<lefttexture>osdprogressleft.png</lefttexture>
<midtexture>osdprogressmid.png</midtexture>
<righttexture>osdprogressright.png</righttexture>
<visible>window.isosdvisible|window.ispauseosdvisible|player.rewinding|player.forwarding|control.isvisible(10)|player.seeking</visible>
</control>
working common.progressbar.xml
<control>
<description>Progress Bar</description>
<type>tvprogress</type>
<id>105</id>
<posX>288</posX>
<posY>1028</posY>
<width>1358</width>
<!--height>15</height-->
<toptexture>-</toptexture>
<TextureOffsetY>0</TextureOffsetY>
<bottomtexture>-</bottomtexture>
<texturetick>-</texturetick>
<!--lefttexture>osdprogressleft.png</lefttexture-->
<midtexture>-</midtexture>
<righttexture>-</righttexture>
<logotexture>-</logotexture>
<fillbackgroundtexture>-</fillbackgroundtexture>
<fillbgxoff>-3</fillbgxoff>
<fillbgyoff>0</fillbgyoff>
<filltexture1>osdprogressmid.png</filltexture1>
<filltexture2>osdprogressmid.png</filltexture2>
<filltexture3>osdprogressmid_orange.png</filltexture3>
<markertexture>osdprogress_comskip_marker.png</markertexture>
<!--fillheight>15</fillheight-->
<label>#percentage</label>
<label1>#percent2</label1>
<label2>#percent3</label2>
<labelmarkerstarts>#jumppoints</labelmarkerstarts>
<labelmarkerends>#chapters</labelmarkerends>
<visible>window.isosdvisible|window.ispauseosdvisible|player.rewinding|player.forwarding|control.isvisible(10)|player.seeking</visible>
</control>