Disable toggling of Overwrite mode when insert key is pressed.

Added a flag to enable/disable toggle mode when insert key is pressed
This is currently disabled by-default.

Bug: 1030231

Change-Id: I9c2dd62c0afe24d27848d189bf151d6a87a64068
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2473771
Reviewed-by: Eric Lawrence [MSFT] <[email protected]>
Reviewed-by: Yoshifumi Inoue <[email protected]>
Reviewed-by: Ian Kilpatrick <[email protected]>
Reviewed-by: Avi Drissman <[email protected]>
Commit-Queue: Anupam Snigdha <[email protected]>
Cr-Commit-Position: refs/heads/master@{#818145}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 9e3a5ad6..90fe643 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -759,6 +759,9 @@
 extern const char kInProductHelpDemoModeChoiceName[];
 extern const char kInProductHelpDemoModeChoiceDescription[];
 
+extern const char kInsertKeyToggleModeName[];
+extern const char kInsertKeyToggleModeDescription[];
+
 extern const char kInstalledAppsInCbdName[];
 extern const char kInstalledAppsInCbdDescription[];