[Cronet] HistogramManager now ensures that StatisticsRecorder is initialized.

components/cronet/android/histogram_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/cronet/android/histogram_manager.h"
 
 #include <string>
 #include <vector>
 
 #include "base/android/jni_array.h"
+#include "base/metrics/statistics_recorder.h"
 #include "components/metrics/histogram_manager.h"
 
 #include "jni/HistogramManager_jni.h"
 
 namespace cronet {
 
 // Explicitly register static JNI functions.
 bool HistogramManagerRegisterJni(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
+static void EnsureInitialized(JNIEnv* env, jobject jcaller) {
+  base::StatisticsRecorder::Initialize();
+}
+
 static jbyteArray GetHistogramDeltas(JNIEnv* env, jobject jcaller) {
   std::vector<uint8> data;
   if (!metrics::HistogramManager::GetInstance()->GetDeltas(&data))
     return NULL;
   return base::android::ToJavaByteArray(env, &data[0], data.size()).Release();
 }
 
 }  // namespace cronet