InfoWindow closing icon not showing in Google Map

Here is the solution for the problem... It seems google maps have some fun way of dealing with images and there was a problem with css as we thought. So the solution is just to add this to your css file:

img 
{
    max-width: none;
}

That's it, enjoy.

I had the same problem. In my case, the infowindow does not show the pointer to the marker. There are some weird looking images in the infowindow as well.

Apparently this has to do with the stylesheet from bootstrap conflicting with google. The following is a much more specific CSS rather than overriding the general CSS

/** FIX for Bootstrap and Google Maps Info window styes problem **/
img[src*="gstatic.com/"], img[src*="googleapis.com/"] {
max-width: none;
}

Depending on other css styling you may need to add the !important override...

img[src*="gstatic.com/"], img[src*="googleapis.com/"] {
max-width: none !important;
}