add drawArraysInstanced to caps

src/gpu/gl/GrGLCaps.cpp

Index: src/gpu/gl/GrGLCaps.cpp
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 22fd053c1d46ab92c9db192302c2a9a87a864443..2ef2f3cc3900c5dfbbda82cf516ed166c3af0e0e 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -448,6 +448,20 @@ void GrGLCaps::init(const GrContextOptions& contextOptions,
         fOversizedStencilSupport = ctxInfo.version() >= GR_GL_VER(3, 0);
     }
 
+    if (kGL_GrGLStandard == standard) {
+        // 3.1 has draw_instanced but not instanced_arrays, for the time being we only care about
+        // instanced arrays, but we could make this more granular if we wanted
+        fSupportsInstancedDraws =
+                version >= GR_GL_VER(3, 2) ||
+                (ctxInfo.hasExtension("GL_ARB_draw_instanced") &&
+                 ctxInfo.hasExtension("GL_ARB_instanced_arrays"));
+    } else {
+        fSupportsInstancedDraws =
+                version >= GR_GL_VER(3, 0) ||
+                (ctxInfo.hasExtension("GL_EXT_draw_instanced") &&
+                 ctxInfo.hasExtension("GL_EXT_instanced_arrays"));
+    }
+
     this->initConfigTexturableTable(ctxInfo, gli);
     this->initConfigRenderableTable(ctxInfo);
     this->initShaderPrecisionTable(ctxInfo, gli, glslCaps);