Revert to old behavior for swap buffers

bench/nanobench.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <ctype.h>
 
 #include "nanobench.h"
@@ skipping 138 matching lines @@
     SkGLContext* gl;
 
     void setup() override {
         this->gl->makeCurrent();
         // Make sure we're done with whatever came before.
         SK_GL(*this->gl, Finish());
     }
     void endTiming() override {
         if (this->gl) {
             SK_GL(*this->gl, Flush());
-            this->gl->swapBuffers();
+            this->gl->waitOnSyncOrSwap();
         }
     }
     void fence() override {
         SK_GL(*this->gl, Finish());
     }
 
     bool needsFrameTiming(int* maxFrameLag) const override {
         if (!this->gl->getMaxGpuFrameLag(maxFrameLag)) {
             // Frame lag is unknown.
             *maxFrameLag = FLAGS_gpuFrameLag;
@@ skipping 1088 matching lines @@
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return nanobench_main();
 }
 #endif