Enable stencil clipping in mixed sampled render targets

src/gpu/gl/GrGLInterface.cpp

Index: src/gpu/gl/GrGLInterface.cpp
diff --git a/src/gpu/gl/GrGLInterface.cpp b/src/gpu/gl/GrGLInterface.cpp
index ec51797c7e81cf246b0c39e5df4878414d4c8e87..91c973b7cb36c3e57cb32552d4e98fd9e37cf3be 100644
--- a/src/gpu/gl/GrGLInterface.cpp
+++ b/src/gpu/gl/GrGLInterface.cpp
@@ -701,6 +701,18 @@ bool GrGLInterface::validate() const {
         }
     }
 
+    if (glVer >= GR_GL_VER(4,3)) {

[Chris Dalton, 2015/09/22 08:35:24]

I think we also need to check the GL standard and make sure it isn't GLES before
validating FramebufferParameteri.

+        if (NULL == fFunctions.fFramebufferParameteri) {
+            RETURN_FALSE_INTERFACE
+        }
+        if (NULL == fFunctions.fNamedFramebufferSampleLocationsfv) {

[Chris Dalton, 2015/09/22 08:35:24]

We should validate for this method when GL_NV_sample_locations is present,
correct? (Not GL version 4.3?)

+            RETURN_FALSE_INTERFACE
+        }
+        if (NULL == fFunctions.fGetMultisamplefv) {

[Chris Dalton, 2015/09/22 08:35:24]

We can validate for this method on GL 3.2 and GLES 3.1.

+            RETURN_FALSE_INTERFACE
+        }
+    }
+
     if ((kGL_GrGLStandard == fStandard && glVer >= GR_GL_VER(4,3)) ||
         fExtensions.has("GL_KHR_debug")) {
         if (nullptr == fFunctions.fDebugMessageControl ||