Make SkGLContext lifetime more well-defined

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 157 matching lines @@
     }
     bool init(SkImageInfo info, Benchmark* bench) override {
         uint32_t flags = this->config.useDFText ? SkSurfaceProps::kUseDeviceIndependentFonts_Flag :
                                                   0;
         SkSurfaceProps props(flags, SkSurfaceProps::kLegacyFontHost_InitType);
         this->surface.reset(SkSurface::NewRenderTarget(gGrFactory->get(this->config.ctxType,
                                                                        this->config.ctxOptions),
                                                          SkSurface::kNo_Budgeted, info,
                                                          this->config.samples, &props));
         this->gl = gGrFactory->getContextInfo(this->config.ctxType,
-                                              this->config.ctxOptions)->fGLContext;
+                                              this->config.ctxOptions).fGLContext;
         if (!this->surface.get()) {
             return false;
         }
         if (!this->gl->fenceSyncSupport()) {
             SkDebugf("WARNING: GL context for config \"%s\" does not support fence sync. "
                      "Timings might not be accurate.\n", this->config.name);
         }
         return true;
     }
     void fillOptions(ResultsWriter* log) override {
@@ skipping 1034 matching lines @@
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return nanobench_main();
 }
 #endif