CrOS Shelf: Add three flags for new UI, dense, scrollable

Bug: 973476, 973483, 973481
Change-Id: I4c94bf8113cad669cd5312bdff6685b1e9f15cbf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1663402
Reviewed-by: Alex Newcomer <[email protected]>
Commit-Queue: Manu Cornet <[email protected]>
Cr-Commit-Position: refs/heads/master@{#670200}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 69ef78d..64c347f 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -980,9 +980,18 @@
 extern const char kSharingDeviceRegistrationName[];
 extern const char kSharingDeviceRegistrationDescription[];
 
+extern const char kShelfDenseClamshellName[];
+extern const char kShelfDenseClamshellDescription[];
+
 extern const char kShelfHoverPreviewsName[];
 extern const char kShelfHoverPreviewsDescription[];
 
+extern const char kShelfNewUiName[];
+extern const char kShelfNewUiDescription[];
+
+extern const char kShelfScrollableName[];
+extern const char kShelfScrollableDescription[];
+
 extern const char kShowAndroidFilesInFilesAppName[];
 extern const char kShowAndroidFilesInFilesAppDescription[];