Add lucid sleep flag and debugging helper

Add a flag for lucid sleep so that apps that wish to start working with it can
do so while it's still under development.  Also to help with testing when the
lid is closed, add a class that will flash the light bar when the system is in dark
resume.

BUG=397328

Signed-off-by: Chirantan Ekbote <[email protected]>

Review URL: https://codereview.chromium.org/566993002

Cr-Commit-Position: refs/heads/master@{#294972}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 1dbc139..a1d3a56 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1905,6 +1905,15 @@
         switches::kEnableMessageCenterAlwaysScrollUpUponNotificationRemoval)
   },
 #endif
+#if defined(OS_CHROMEOS)
+  {
+    "wake-on-packets",
+    IDS_FLAGS_WAKE_ON_PACKETS_NAME,
+    IDS_FLAGS_WAKE_ON_PACKETS_DESCRIPTION,
+    kOsCrOSOwnerOnly,
+    SINGLE_VALUE_TYPE(chromeos::switches::kWakeOnPackets)
+  },
+#endif  // OS_CHROMEOS
   // NOTE: Adding new command-line switches requires adding corresponding
   // entries to enum "LoginCustomFlags" in histograms.xml. See note in
   // histograms.xml and don't forget to run AboutFlagsHistogramTest unit test.