One signature for creating unit tests that run on premade GrContexts

tests/SRGBReadWritePixelsTest.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 #if SK_SUPPORT_GPU
 #include "GrCaps.h"
@@ skipping 120 matching lines @@
                 ERRORF(reporter, "Expected 0x%08x, read back as 0x%08x in %s at %d, %d).",
                        orig, read, subtestName, i, j);
                 return;
             }
         }
     }
 }
 
 // TODO: Add tests for copySurface between srgb/linear textures. Add tests for unpremul/premul
 // conversion during read/write along with srgb/linear conversions.
-DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SRGBReadWritePixels, reporter, context) {
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SRGBReadWritePixels, reporter, ctxInfo) {
+    GrContext* context = ctxInfo.fGrContext;
 #if defined(GOOGLE3)
     // Stack frame size is limited in GOOGLE3.
     static const int kW = 63;
     static const int kH = 63;
 #else
     static const int kW = 255;
     static const int kH = 255;
 #endif
     uint32_t origData[kW * kH];
     for (int j = 0; j < kH; ++j) {
@@ skipping 71 matching lines @@
         if (tex->writePixels(0, 0, kW, kH, kRGBA_8888_GrPixelConfig, origData)) {
             read_and_check_pixels(reporter, tex, origData, kSRGBA_8888_GrPixelConfig,
                                   check_linear_to_srgb_conversion, 1.2f,
                                   "write rgba/read srgba to rgba texture");
         } else {
             ERRORF(reporter, "Could not write rgba data to rgba texture.");
         }
     }
 }
 #endif