[Sync] - In about:sync page display if the first sync after restart has taken place or not.

chrome/browser/sync/sync_ui_util.cc

Index: chrome/browser/sync/sync_ui_util.cc
diff --git a/chrome/browser/sync/sync_ui_util.cc b/chrome/browser/sync/sync_ui_util.cc
index 8cf7b78b9bfa7bd08f2b74ee37ad649245890702..cbe92d61d9217ba1c45ef5851d5e7d7ff41f475a 100644
--- a/chrome/browser/sync/sync_ui_util.cc
+++ b/chrome/browser/sync/sync_ui_util.cc
@@ -511,6 +511,14 @@ void ConstructAboutInformation(ProfileSyncService* service,
                        ProfileSyncService::BuildSyncStatusSummaryText(
                        full_status.summary));
 
+    if (full_status.summary == sync_api::SyncManager::Status::UNINITIALIZED) {
+      strings->Set("summary_explanation_needed",
+                   new base::FundamentalValue(true));
+      std::string message = "A sync has not happened since restart. ";
+      message += "The following values are speculative.";
+      strings->SetString("summary_explanation_message", message);
+    }
+
     strings->SetString("version", GetVersionString());
     strings->Set("authenticated",
                  new base::FundamentalValue(full_status.authenticated));