cros: Expose new overview ui from flag.

Test: unit_tests AboutFlagsHistogramTest.CheckHistograms
Bug: 782320
Change-Id: I9b75d6e9b9e018b86a8d011653f02887e2a68f1e
Reviewed-on: https://chromium-review.googlesource.com/889920
Commit-Queue: Sammie Quon <[email protected]>
Reviewed-by: Mitsuru Oshima <[email protected]>
Cr-Commit-Position: refs/heads/master@{#533054}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 8e77c20..5374dbf 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -1809,6 +1809,9 @@
 extern const char kAshEnableMirroredScreenName[];
 extern const char kAshEnableMirroredScreenDescription[];
 
+extern const char kAshEnableNewOverviewUiName[];
+extern const char kAshEnableNewOverviewUiDescription[];
+
 extern const char kAshEnablePersistentWindowBoundsName[];
 extern const char kAshEnablePersistentWindowBoundsDescription[];