[NTPSnippets] Records the time since last successful bg fetch.

chrome/browser/android/ntp/ntp_snippets_bridge.cc

 // Copyright 2016 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 "chrome/browser/android/ntp/ntp_snippets_bridge.h"
 
 #include <jni.h>
 #include <utility>
 #include <vector>
 
 #include "base/android/callback_android.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/callback.h"
 #include "base/time/time.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/ntp_snippets/content_suggestions_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_android.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "components/history/core/browser/history_service.h"
 #include "components/ntp_snippets/content_suggestion.h"
 #include "components/ntp_snippets/content_suggestions_metrics.h"
+#include "components/ntp_snippets/pref_names.h"
 #include "components/ntp_snippets/remote/remote_suggestions_provider.h"
+#include "components/prefs/pref_service.h"
 #include "jni/SnippetsBridge_jni.h"
 #include "ui/base/window_open_disposition.h"
 #include "ui/gfx/android/java_bitmap.h"
 #include "ui/gfx/image/image.h"
 
 using base::android::AttachCurrentThread;
 using base::android::ConvertJavaStringToUTF8;
 using base::android::ConvertUTF8ToJavaString;
 using base::android::ConvertUTF16ToJavaString;
 using base::android::JavaIntArrayToIntVector;
@@ skipping 307 matching lines @@
       ntp_snippets::UserClassifier::Metric::NTP_OPENED);
 }
 
 void NTPSnippetsBridge::OnSuggestionShown(JNIEnv* env,
                                           const JavaParamRef<jobject>& obj,
                                           jint global_position,
                                           jint j_category_id,
                                           jint category_position,
                                           jlong publish_timestamp_ms,
                                           jfloat score) {
+  PrefService* pref_service = ProfileManager::GetLastUsedProfile()->GetPrefs();
+  base::Time last_background_fetch_time =
+      base::Time::FromInternalValue(pref_service->GetInt64(
+          ntp_snippets::prefs::kLastSuccessfulBackgroundFetchTime));
+
   ntp_snippets::metrics::OnSuggestionShown(
       global_position, CategoryFromIDValue(j_category_id), category_position,
-      base::Time::FromJavaTime(publish_timestamp_ms), score);
+      base::Time::FromJavaTime(publish_timestamp_ms),
+      last_background_fetch_time, score);
   if (global_position == 0) {
     content_suggestions_service_->user_classifier()->OnEvent(
         ntp_snippets::UserClassifier::Metric::SUGGESTIONS_SHOWN);
   }
 }
 
 void NTPSnippetsBridge::OnSuggestionOpened(JNIEnv* env,
                                            const JavaParamRef<jobject>& obj,
                                            jint global_position,
                                            jint j_category_id,
@@ skipping 110 matching lines @@
 }
 
 Category NTPSnippetsBridge::CategoryFromIDValue(jint id) {
   return content_suggestions_service_->category_factory()->FromIDValue(id);
 }
 
 // static
 bool NTPSnippetsBridge::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }