skia: Make the validate match interface for *_draw_instanced

src/gpu/gl/GrGLAssembleInterface.cpp

Index: src/gpu/gl/GrGLAssembleInterface.cpp
diff --git a/src/gpu/gl/GrGLAssembleInterface.cpp b/src/gpu/gl/GrGLAssembleInterface.cpp
index 294e6dfaef877a67f21ca5e8127bda21f6f2576c..c4d3e1317978ba1e3973514d564b87899df36721 100644
--- a/src/gpu/gl/GrGLAssembleInterface.cpp
+++ b/src/gpu/gl/GrGLAssembleInterface.cpp
@@ -317,7 +317,8 @@ const GrGLInterface* GrGLAssembleGLInterface(void* ctx, GrGLGetProc get) {
         GET_PROC(GetProgramResourceLocation);
     }
 
-    if (glVer >= GR_GL_VER(3,1) || extensions.has("GL_ARB_draw_instanced")) {
+    if (glVer >= GR_GL_VER(3,1) || extensions.has("GL_ARB_draw_instanced") ||
+        extensions.has("GL_EXT_draw_instanced")) {
         GET_PROC(DrawArraysInstanced);
         GET_PROC(DrawElementsInstanced);
     }