Casey, I think you should check also for GL_ARB_framebuffer_sRGB extension. Currently you are only checking for GL_EXT_framebuffer_sRGB extension to enable sRGB framebuffer.

But ARB extension is more common. See here: http://delphigl.de/glcapsviewer/gl_extensions.php
GL_ARB_framebuffer_sRGB = 84.13%
GL_EXT_framebuffer_sRGB = 68.86%

Of course if you are asking for 3.0 context, this is all a bit irrelevant. sRGB support is mandatory for OpenGL versions 3.0 or up. You might as well set Result.GL_EXT_texture_sRGB boolean always to true. wglCreateContextAttribsARB will simply fail if GPU/driver doesn't support 3.0 version.

But this might be relevant for other ARB/EXT extensions if they will be used.