nanobench: flush after recording every Nth data point.

bench/ResultsWriter.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  * Classes for writing out bench results in various formats.
  */
 
 #ifndef SkResultsWriter_DEFINED
@@ skipping 27 matching lines @@
     virtual void bench(const char name[], int32_t x, int32_t y) {}
 
     // Record the specific configuration a bench is run under, such as "8888".
     virtual void config(const char name[]) {}
 
     // Record the options for a configuration, such as "GL_RENDERER".
     virtual void configOption(const char name[], const char* value) {}
 
     // Record a single test metric.
     virtual void timer(const char name[], double ms) {}
+
+    // Flush to storage now please.
+    virtual void flush() {}
 };
 
 /**
  NanoJSONResultsWriter writes the test results out in the following
  format:
 
  {
     "key": {
       "arch": "Arm7",
       "gpu": "SGX540",
@@ skipping 14 matching lines @@
 class NanoJSONResultsWriter : public ResultsWriter {
 public:
     explicit NanoJSONResultsWriter(const char filename[])
         : fFilename(filename)
         , fRoot()
         , fResults(fRoot["results"])
         , fBench(NULL)
         , fConfig(NULL) {}
 
     ~NanoJSONResultsWriter() {
-        SkFILEWStream stream(fFilename.c_str());
-        stream.writeText(Json::StyledWriter().write(fRoot).c_str());
-        stream.flush();
+        this->flush();
     }
 
     // Added under "key".
     virtual void key(const char name[], const char value[]) {
         fRoot["key"][name] = value;
     }
     // Inserted directly into the root.
     virtual void property(const char name[], const char value[]) {
         fRoot[name] = value;
     }
@@ skipping 11 matching lines @@
     }
     virtual void timer(const char name[], double ms) {
         // Don't record if nan, or -nan.
         if (sk_double_isnan(ms)) {
             return;
         }
         SkASSERT(fConfig);
         (*fConfig)[name] = ms;
     }
 
+    // Flush to storage now please.
+    virtual void flush() {
+        SkFILEWStream stream(fFilename.c_str());
+        stream.writeText(Json::StyledWriter().write(fRoot).c_str());
+        stream.flush();
+    }
+
 private:
     SkString fFilename;
     Json::Value fRoot;
     Json::Value& fResults;
     Json::Value* fBench;
     Json::Value* fConfig;
 };
 
 
 #endif