Another speculative ASAN fix.

tests/SurfaceTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkImageEncoder.h"
@@ skipping 233 matching lines @@
         { kGpu_ImageType,           false,      "Gpu"           },
         { kCodec_ImageType,         false,      "Codec"         },
     };
 
     const SkColor color = SK_ColorRED;
     const SkPMColor pmcolor = SkPreMultiplyColor(color);
 
     GrContext* ctx = NULL;
 #if SK_SUPPORT_GPU
     ctx = factory->get(GrContextFactory::kNative_GLContextType);
+    if (!ctx) {
+        return;
+    }
 #endif
 
     for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
         SkImageInfo info;
         size_t rowBytes;
 
         SkAutoTUnref<SkImage> image(createImage(gRec[i].fType, ctx, color));
         if (!image.get()) {
             SkDebugf("failed to createImage[%d] %s\n", i, gRec[i].fName);
             continue;   // gpu may not be enabled
@@ skipping 343 matching lines @@
                 TestGetTexture(reporter, kGpu_SurfaceType, context);
                 TestGetTexture(reporter, kGpuScratch_SurfaceType, context);
                 test_empty_surface(reporter, context);
                 test_surface_budget(reporter, context);
                 test_wrapped_texture_surface(reporter, context);
             }
         }
     }
 #endif
 }