[NTP Snippets] Clean up NTPSnippetsServiceTests

components/ntp_snippets/ntp_snippet.cc

Index: components/ntp_snippets/ntp_snippet.cc
diff --git a/components/ntp_snippets/ntp_snippet.cc b/components/ntp_snippets/ntp_snippet.cc
index d21e4913fd1a0d9e7baee767990326068f33f510..863f5770a6f147d07ce91c8e7bdd1d2f26b99f97 100644
--- a/components/ntp_snippets/ntp_snippet.cc
+++ b/components/ntp_snippets/ntp_snippet.cc
@@ -56,29 +56,13 @@ std::unique_ptr<NTPSnippet> NTPSnippet::CreateFromDictionary(
   std::string snippet_str;
   if (dict.GetString(kSnippet, &snippet_str))
     snippet->set_snippet(snippet_str);
-  // creationTimestampSec is a uint64, which is stored using strings
+  // The creation and expiry timestamps are uint64s which are stored as strings.
   std::string creation_timestamp_str;
-  if (dict.GetString(kPublishDate, &creation_timestamp_str)) {
-    int64_t creation_timestamp = 0;
-    if (!base::StringToInt64(creation_timestamp_str, &creation_timestamp)) {
-      // Even if there's an error in the conversion, some garbage data may still
-      // be written to the output var, so reset it
-      creation_timestamp = 0;
-    }
-    snippet->set_publish_date(base::Time::UnixEpoch() +
-                              base::TimeDelta::FromSeconds(creation_timestamp));
-  }
+  if (dict.GetString(kPublishDate, &creation_timestamp_str))
+    snippet->set_publish_date(TimeFromJsonString(creation_timestamp_str));
   std::string expiry_timestamp_str;
-  if (dict.GetString(kExpiryDate, &expiry_timestamp_str)) {
-    int64_t expiry_timestamp = 0;
-    if (!base::StringToInt64(expiry_timestamp_str, &expiry_timestamp)) {
-      // Even if there's an error in the conversion, some garbage data may still
-      // be written to the output var, so reset it
-      expiry_timestamp = 0;
-    }
-    snippet->set_expiry_date(base::Time::UnixEpoch() +
-                             base::TimeDelta::FromSeconds(expiry_timestamp));
-  }
+  if (dict.GetString(kExpiryDate, &expiry_timestamp_str))
+    snippet->set_expiry_date(TimeFromJsonString(expiry_timestamp_str));
 
   return snippet;
 }
@@ -97,18 +81,28 @@ std::unique_ptr<base::DictionaryValue> NTPSnippet::ToDictionary() const {
     dict->SetString(kSalientImageUrl, salient_image_url_.spec());
   if (!snippet_.empty())
     dict->SetString(kSnippet, snippet_);
-  if (!publish_date_.is_null()) {
-    dict->SetString(kPublishDate,
-                    base::Int64ToString(
-                        (publish_date_ - base::Time::UnixEpoch()).InSeconds()));
-  }
-  if (!expiry_date_.is_null()) {
-    dict->SetString(kExpiryDate,
-                    base::Int64ToString(
-                        (expiry_date_ - base::Time::UnixEpoch()).InSeconds()));
-  }
+  if (!publish_date_.is_null())
+    dict->SetString(kPublishDate, TimeToJsonString(publish_date_));
+  if (!expiry_date_.is_null())
+    dict->SetString(kExpiryDate, TimeToJsonString(expiry_date_));
 
   return dict;
 }
 
+// static
+base::Time NTPSnippet::TimeFromJsonString(const std::string& timestamp_str) {
+  int64_t timestamp;
+  if (!base::StringToInt64(timestamp_str, &timestamp)) {
+    // Even if there's an error in the conversion, some garbage data may still
+    // be written to the output var, so reset it.
+    timestamp = 0;
+  }
+  return base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(timestamp);
+}
+
+// static
+std::string NTPSnippet::TimeToJsonString(const base::Time& time) {
+  return base::Int64ToString((time - base::Time::UnixEpoch()).InSeconds());
+}
+
 }  // namespace ntp_snippets