Add ES 3.0 fallback for instanced rendering

src/gpu/gl/GrGLCaps.h

Index: src/gpu/gl/GrGLCaps.h
diff --git a/src/gpu/gl/GrGLCaps.h b/src/gpu/gl/GrGLCaps.h
index 0cb353aa9f78703654d17c3731027054b5e36a5a..3408ae0e8fddef5589034283d543bf07f82d7a3b 100644
--- a/src/gpu/gl/GrGLCaps.h
+++ b/src/gpu/gl/GrGLCaps.h
@@ -296,6 +296,9 @@ public:
     /// Is there support for ES2 compatability?
     bool ES2CompatibilitySupport() const { return fES2CompatibilitySupport; }
 
+    /// Is there support for glDraw*Instanced?
+    bool drawInstancedSupport() const { return fDrawInstancedSupport; }
+
     /// Is there support for glDraw*Indirect? Note that the baseInstance fields of indirect draw
     /// commands cannot be used unless we have base instance support.
     bool drawIndirectSupport() const { return fDrawIndirectSupport; }
@@ -395,6 +398,7 @@ private:
     bool fDirectStateAccessSupport : 1;
     bool fDebugSupport : 1;
     bool fES2CompatibilitySupport : 1;
+    bool fDrawInstancedSupport : 1;
     bool fDrawIndirectSupport : 1;
     bool fMultiDrawIndirectSupport : 1;
     bool fBaseInstanceSupport : 1;