Plumbed in discard_framebuffer extension

src/gpu/gl/GrGLInterface.cpp

Index: src/gpu/gl/GrGLInterface.cpp
===================================================================
--- src/gpu/gl/GrGLInterface.cpp	(revision 8892)
+++ src/gpu/gl/GrGLInterface.cpp	(working copy)
@@ -295,6 +295,12 @@
         }
     }
 
+    if (extensions.has("GL_EXT_discard_framebuffer")) {

[bsalomon, 2013/04/29 14:42:15]

Might be worth checking if Chrome passes along this extension. If not, we need
to get it. If so we have to skip this check until Chrome gives us the ptr.

[robertphillips, 2013/04/29 15:25:39]

Done.

+        if (NULL == fDiscardFramebuffer) {
+            return false;
+        }
+    }
+
     // FBO MSAA
     if (kDesktop_GrGLBinding == binding) {
         // GL 3.0 and the ARB extension have multisample + blit