Devirtualize read/write pixels on surface.

src/gpu/GrDistanceFieldTextContext.cpp

Index: src/gpu/GrDistanceFieldTextContext.cpp
diff --git a/src/gpu/GrDistanceFieldTextContext.cpp b/src/gpu/GrDistanceFieldTextContext.cpp
index a1f5ce66608bac5cdf9ab934faffde042257f25d..183b83c3e6e7ef8b5baf478663cc5824276e3826 100755
--- a/src/gpu/GrDistanceFieldTextContext.cpp
+++ b/src/gpu/GrDistanceFieldTextContext.cpp
@@ -190,10 +190,9 @@ static void setup_gamma_texture(GrContext* context, const SkGlyphCache* cache,
             return;
         }
 
-        context->writeTexturePixels(*gammaTexture,
-                                    0, 0, width, height,
-                                    (*gammaTexture)->config(), data.get(), 0,
-                                    GrContext::kDontFlush_PixelOpsFlag);
+        (*gammaTexture)->writePixels(0, 0, width, height,
+                                     (*gammaTexture)->config(), data.get(), 0,
+                                     GrContext::kDontFlush_PixelOpsFlag);
     }
 }