Add feature flag for short notification time outs.

This will be enabled by a finch experiment to reduce
timeouts to 6 seconds for a specific group of users.

Bug: 1059017
Change-Id: Ie2a22c1b7f39856c57133df0992238419439f1c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2096901Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Ahmed Mehfooz <amehfooz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748862}

ash/public/cpp/ash_features.cc

@@ -66,6 +66,9 @@ const base::Feature kNightLight{"NightLight", base::FEATURE_ENABLED_BY_DEFAULT};
 const base::Feature kNotificationExpansionAnimation{
     "NotificationExpansionAnimation", base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kNotificationExperimentalShortTimeouts{
+    "NotificationExperimentalShortTimeouts", base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kNotificationScrollBar{"NotificationScrollBar",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
@@ -148,6 +151,10 @@ bool IsNotificationScrollBarEnabled() {
   return base::FeatureList::IsEnabled(kNotificationScrollBar);
 }
 
+bool IsNotificationExperimentalShortTimeoutsEnabled() {
+  return base::FeatureList::IsEnabled(kNotificationExperimentalShortTimeouts);
+}
+
 bool IsPipRoundedCornersEnabled() {
   return base::FeatureList::IsEnabled(kPipRoundedCorners);
 }

ash/public/cpp/ash_features.h

@@ -84,6 +84,10 @@ ASH_PUBLIC_EXPORT extern const base::Feature kNightLight;
 // Enabled notification expansion animation.
 ASH_PUBLIC_EXPORT extern const base::Feature kNotificationExpansionAnimation;
 
+// Shorten notification timeouts to 6 seconds.
+ASH_PUBLIC_EXPORT extern const base::Feature
+    kNotificationExperimentalShortTimeouts;
+
 // Enables notification scroll bar in UnifiedSystemTray.
 ASH_PUBLIC_EXPORT extern const base::Feature kNotificationScrollBar;
 
@@ -160,6 +164,8 @@ ASH_PUBLIC_EXPORT bool IsLockScreenHideSensitiveNotificationsSupported();
 
 ASH_PUBLIC_EXPORT bool IsNotificationExpansionAnimationEnabled();
 
+ASH_PUBLIC_EXPORT bool IsNotificationExperimentalShortTimeoutsEnabled();
+
 ASH_PUBLIC_EXPORT bool IsNotificationScrollBarEnabled();
 
 ASH_PUBLIC_EXPORT bool IsPipRoundedCornersEnabled();