[TablesNG] Chrome flag to enable TablesNG

Adds flag to enable TablesNG to Chrome.
Off by default.
Plan is for tables to be feature complete by Dec 4th.
This is the first public step towards TablesNG release.

Bug: 958381
Change-Id: Idce9980395cbfc860fa4fd5834e56db9bc7cdfc9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2566251
Commit-Queue: Aleks Totic <[email protected]>
Reviewed-by: Ian Kilpatrick <[email protected]>
Cr-Commit-Position: refs/heads/master@{#832152}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index a664609..494edb6 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -456,6 +456,9 @@
 extern const char kEnableLayoutNGName[];
 extern const char kEnableLayoutNGDescription[];
 
+extern const char kEnableLayoutNGTableName[];
+extern const char kEnableLayoutNGTableDescription[];
+
 extern const char kEnableLazyFrameLoadingName[];
 extern const char kEnableLazyFrameLoadingDescription[];