Implement the Notification `timestamp` property

content/child/notifications/notification_data_conversions.cc

Index: content/child/notifications/notification_data_conversions.cc
diff --git a/content/child/notifications/notification_data_conversions.cc b/content/child/notifications/notification_data_conversions.cc
index 9f05f0d0b61f3719bd8fb0cd3769c95477c6bbf0..371967ad8e657554b21ac501a7320e0281944ce9 100644
--- a/content/child/notifications/notification_data_conversions.cc
+++ b/content/child/notifications/notification_data_conversions.cc
@@ -5,6 +5,7 @@
 #include "content/child/notifications/notification_data_conversions.h"
 
 #include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
@@ -40,6 +41,7 @@ PlatformNotificationData ToPlatformNotificationData(
   platform_data.icon = GURL(web_data.icon.string());
   platform_data.vibration_pattern.assign(web_data.vibrate.begin(),
                                          web_data.vibrate.end());
+  platform_data.timestamp = base::Time::FromJsTime(web_data.timestamp);

[johnme, 2015/10/20 17:12:21]

If JS passes MAX_ULL, it'll overflow base::Time, since:
a) base::Time uses an earlier epoch (1601)
b) base::Time is signed so has half the range
It looks like operator+ handles that sensibly, but it won't round-trip to the
same value, so please add a test.

[Peter Beverloo, 2016/01/28 17:18:29]

Done.

   platform_data.silent = web_data.silent;
   platform_data.require_interaction = web_data.requireInteraction;
   platform_data.data.assign(web_data.data.begin(), web_data.data.end());
@@ -75,6 +77,7 @@ WebNotificationData ToWebNotificationData(
   web_data.tag = blink::WebString::fromUTF8(platform_data.tag);
   web_data.icon = blink::WebURL(platform_data.icon);
   web_data.vibrate = platform_data.vibration_pattern;
+  web_data.timestamp = platform_data.timestamp.ToJsTime();

[johnme, 2015/10/20 17:12:21]

I don't think underflow is possible, and I think zero will round-trip correctly,
but perhaps add a test for the latter anyway?

[Peter Beverloo, 2016/01/28 17:18:29]

Done.

   web_data.silent = platform_data.silent;
   web_data.requireInteraction = platform_data.require_interaction;
   web_data.data = platform_data.data;