micro fix for rrects bug using GrDrawContext

gm/rrects.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
@@ skipping 49 matching lines @@
         return name;
     }
 
     SkISize onISize() override { return SkISize::Make(kImageWidth, kImageHeight); }
 
     void onDraw(SkCanvas* canvas) override {
         GrContext* context = nullptr;
 #if SK_SUPPORT_GPU
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
         context = rt ? rt->getContext() : nullptr;
-        SkAutoTUnref<GrDrawContext> drawContext(context->drawContext(rt));
-        if (!drawContext) {
-            return;
+        SkAutoTUnref<GrDrawContext> drawContext;
+        if (kEffect_Type == fType) {
+            if (!context) {
+                skiagm::GM::DrawGpuOnlyMessage(canvas);
+                return;
+            }
+
+            drawContext.reset(context->drawContext(rt));
+            if (!drawContext) {
+                return;
+            }
         }
 #endif
         if (kEffect_Type == fType && nullptr == context) {
             skiagm::GM::DrawGpuOnlyMessage(canvas);
             return;
         }
 
         SkPaint paint;
         if (kAA_Draw_Type == fType) {
             paint.setAntiAlias(true);
@@ skipping 180 matching lines @@
 
 DEF_GM( return new RRectGM(RRectGM::kAA_Draw_Type); )
 DEF_GM( return new RRectGM(RRectGM::kBW_Draw_Type); )
 DEF_GM( return new RRectGM(RRectGM::kAA_Clip_Type); )
 DEF_GM( return new RRectGM(RRectGM::kBW_Clip_Type); )
 #if SK_SUPPORT_GPU
 DEF_GM( return new RRectGM(RRectGM::kEffect_Type); )
 #endif
 
 }