Introduce a new API to handle native notification clicks

chrome/browser/notifications/notification_platform_bridge_mac_unittest.mm

Index: chrome/browser/notifications/notification_platform_bridge_mac_unittest.mm
diff --git a/chrome/browser/notifications/notification_platform_bridge_mac_unittest.mm b/chrome/browser/notifications/notification_platform_bridge_mac_unittest.mm
index 509729a5db138ef14d2fbe42e534c1cde44bfd7f..05d30e51886a6c91367bbdfc88a1c10f8a74948e 100644
--- a/chrome/browser/notifications/notification_platform_bridge_mac_unittest.mm
+++ b/chrome/browser/notifications/notification_platform_bridge_mac_unittest.mm
@@ -5,6 +5,7 @@
 #import <AppKit/AppKit.h>
 
 #include "base/mac/scoped_nsobject.h"
+#include "chrome/browser/notifications/notification_common.h"
 #include "chrome/browser/notifications/notification_platform_bridge_mac.h"
 #include "chrome/browser/ui/cocoa/notifications/notification_builder_mac.h"
 #include "chrome/browser/ui/cocoa/notifications/notification_constants_mac.h"
@@ -26,6 +27,9 @@ NSMutableDictionary* BuildDefaultNotificationResponse() {
   [builder setNotificationId:@"notificationId"];
   [builder setProfileId:@"profileId"];
   [builder setIncognito:false];
+  [builder
+      setNotificationType:[NSNumber
+                              numberWithInt:NotificationCommon::PERSISTENT]];
 
   NSUserNotification* notification = [builder buildUserNotification];
   return [NSMutableDictionary
@@ -40,6 +44,13 @@ TEST(NotificationPlatformBridgeMacTest, TestNotificationValidResponse) {
   EXPECT_TRUE(NotificationPlatformBridgeMac::VerifyNotificationData(response));
 }
 
+TEST(NotificationPlatformBridgeMacTest, TestNotificationUnknownType) {
+  NSMutableDictionary* response = BuildDefaultNotificationResponse();
+  [response setValue:[NSNumber numberWithInt:210581]
+              forKey:notification_constants::kNotificationType];
+  EXPECT_FALSE(NotificationPlatformBridgeMac::VerifyNotificationData(response));
+}
+
 TEST(NotificationPlatformBridgeMacTest, TestNotificationUnknownOperation) {
   NSMutableDictionary* response = BuildDefaultNotificationResponse();
   [response setValue:[NSNumber numberWithInt:40782]