Implement the Notification `timestamp` property

chrome/browser/notifications/platform_notification_service_browsertest.cc

Index: chrome/browser/notifications/platform_notification_service_browsertest.cc
diff --git a/chrome/browser/notifications/platform_notification_service_browsertest.cc b/chrome/browser/notifications/platform_notification_service_browsertest.cc
index 5497866f7f3bafa056e935cec1300758dfae0c5f..664366d4a0fc14acabe77540644208fb161f14c2 100644
--- a/chrome/browser/notifications/platform_notification_service_browsertest.cc
+++ b/chrome/browser/notifications/platform_notification_service_browsertest.cc
@@ -10,6 +10,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
 #include "chrome/browser/notifications/desktop_notification_profile_util.h"
 #include "chrome/browser/notifications/notification_permission_context.h"
 #include "chrome/browser/notifications/notification_permission_context_factory.h"
@@ -36,6 +37,8 @@ const int kIconHeight = 100;
 
 const int kNotificationVibrationPattern[] = { 100, 200, 300 };
 
+const double kNotificationTimestamp = 621046800000.;
+
 class PlatformNotificationServiceBrowserTest : public InProcessBrowserTest {
  public:
   PlatformNotificationServiceBrowserTest();
@@ -245,6 +248,13 @@ IN_PROC_BROWSER_TEST_F(PlatformNotificationServiceBrowserTest,
   EXPECT_EQ("", base::UTF16ToUTF8(default_notification.message()));
   EXPECT_EQ("", default_notification.tag());
   EXPECT_TRUE(default_notification.icon().IsEmpty());
+
+  // Verifies that the notification's default timestamp is set in the last 30
+  // seconds. This number has no significance, but it needs to be significantly
+  // high to avoid flakiness in the test.
+  EXPECT_NEAR(default_notification.timestamp().ToJsTime(),
+              base::Time::Now().ToJsTime(), 30 * 1000);
+
   EXPECT_FALSE(default_notification.silent());
   EXPECT_FALSE(default_notification.never_timeout());
 
@@ -263,6 +273,8 @@ IN_PROC_BROWSER_TEST_F(PlatformNotificationServiceBrowserTest,
   EXPECT_EQ("Contents", base::UTF16ToUTF8(all_options_notification.message()));
   EXPECT_EQ("replace-id", all_options_notification.tag());
   EXPECT_FALSE(all_options_notification.icon().IsEmpty());
+  EXPECT_DOUBLE_EQ(kNotificationTimestamp,
+                   all_options_notification.timestamp().ToJsTime());
   EXPECT_TRUE(all_options_notification.silent());
   EXPECT_TRUE(all_options_notification.never_timeout());