Add _aa variants of Xfermode benches.

bench/Benchmark.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef Benchmark_DEFINED
 #define Benchmark_DEFINED
 
 #include "SkPoint.h"
 #include "SkRefCnt.h"
 #include "SkString.h"
 #include "SkTRegistry.h"
 
-#define DEF_BENCH(code)                                                 \
-namespace {                                                             \
-static Benchmark* SK_MACRO_APPEND_LINE(factory)(void*) { code; }      \
-BenchRegistry SK_MACRO_APPEND_LINE(g_R_)(SK_MACRO_APPEND_LINE(factory)); \
-}
+#define DEF_BENCH3(code, N) \
+    static BenchRegistry gBench##N([](void*) -> Benchmark* { code; });
+#define DEF_BENCH2(code, N) DEF_BENCH3(code, N)
+#define DEF_BENCH(code) DEF_BENCH2(code, __COUNTER__)
 
 /*
  *  With the above macros, you can register benches as follows (at the bottom
  *  of your .cpp)
  *
  *  DEF_BENCH(return new MyBenchmark(...))
  *  DEF_BENCH(return new MyBenchmark(...))
  *  DEF_BENCH(return new MyBenchmark(...))
  */
 
@@ skipping 88 matching lines @@
     int     fForceAlpha;
     SkTriState::State  fDither;
     uint32_t    fOrMask, fClearMask;
 
     typedef SkRefCnt INHERITED;
 };
 
 typedef SkTRegistry<Benchmark*(*)(void*)> BenchRegistry;
 
 #endif