Change requisite hardware checks for enabling multisample framebuffers.

[Roger Fong]

m_maySupportMultisampling should be true by default for all platforms/hardware now except older versions of AMD.

[Roger Fong]

Created attachment 196754 [details]
patch

[Benjamin Poulain]

Comment on attachment 196754 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=196754&action=review

> Source/WebCore/platform/graphics/opengl/Extensions3DOpenGLCommon.cpp:95
> -    if (m_isNVIDIA || (m_isAMD && systemSupportsMultisampling))
> -        m_maySupportMultisampling = true;
> +    if (!(m_isNVIDIA || m_isIntel || (m_isAMD && systemSupportsMultisampling)))
> +        m_maySupportMultisampling = false;

It looks like the previous code would never put m_maySupportMultisampling = false.
 
What about leaving m_maySupportMultisampling uninitialized then?:
    m_maySupportMultisampling = m_isNVIDIA || m_isIntel || (m_isAMD && systemSupportsMultisampling);

[Roger Fong]

I think what we ended up wanting was for it to be true by default for everything except for certain versions of AMD...

O wait...if I wanted to do that I guess I could of just done: 

+    if (m_isAMD && !systemSupportsMultisampling)))
+        m_maySupportMultisampling = false;

[Dean Jackson]

(In reply to comment #3)
> I think what we ended up wanting was for it to be true by default for everything except for certain versions of AMD...
> 
> O wait...if I wanted to do that I guess I could of just done: 
> 
> +    if (m_isAMD && !systemSupportsMultisampling)))
> +        m_maySupportMultisampling = false;

Yeah, do that one!

We should assume other ports want this supported. Meanwhile, we know it isn't good on AMD before a certain version on OS X, so turn it off there. We might have to turn it off on older OS X systems for other hardware too, but we don't know for sure yet.

[Roger Fong]

Created attachment 197163 [details]
patch

[Roger Fong]

Committed:http://trac.webkit.org/changeset/148060