Add optional data parameter to createBuffer

tools/gpu/GrTest.cpp

Index: tools/gpu/GrTest.cpp
diff --git a/tools/gpu/GrTest.cpp b/tools/gpu/GrTest.cpp
index c707b69375f953f5c5dc53e2213d2b2c785cd736..5771a785325fabddac0060b4b685da4212cd0af7 100644
--- a/tools/gpu/GrTest.cpp
+++ b/tools/gpu/GrTest.cpp
@@ -345,7 +345,9 @@ private:
         return nullptr;
     }
 
-    GrBuffer* onCreateBuffer(size_t, GrBufferType, GrAccessPattern) override { return nullptr; }
+    GrBuffer* onCreateBuffer(size_t, GrBufferType, GrAccessPattern, const void*) override {
+        return nullptr;
+    }
 
     void onClear(GrRenderTarget*, const SkIRect& rect, GrColor color) override {}