Remove TODOs to remove the "new back shortcut bubble".

chrome/app/chrome_command_ids.h

Index: chrome/app/chrome_command_ids.h
diff --git a/chrome/app/chrome_command_ids.h b/chrome/app/chrome_command_ids.h
index 0b830f014cc33f4ea9343156fd3c357e6495b3bb..6f4b1d7de273b1c7af7218745b8061577e08ae73 100644
--- a/chrome/app/chrome_command_ids.h
+++ b/chrome/app/chrome_command_ids.h
@@ -29,10 +29,10 @@
 #define IDC_RELOAD_BYPASSING_CACHE      33007
 #define IDC_LOAD_NEW_TAB_PAGE           33008
 #define IDC_RELOAD_CLEARING_CACHE       33009
-// Temporary commands to capture the old Back/Forward shortcuts and tell users
-// the new shortcut. May also trigger Back/Forward action if the
-// BackspaceGoesBack field trial is enabled.
-// TODO(mgiuca): Remove these in M54 (https://crbug.com/610039).
+// Commands to capture the old Back/Forward shortcuts (which users of old Chrome
+// versions or other browsers may be familiar with) and tell users the new
+// shortcut. May also trigger Back/Forward action if the BackspaceGoesBack field
+// trial is enabled.

[Matt Giuca, 2017/03/01 23:35:52]

Also happy to just delete this comment since no other command has a comment
here.

[Peter Kasting, 2017/03/02 23:28:23]

Yeah, I'd delete this comment, and if this information is not captured
elsewhere, seek to add it elsewhere, e.g. in the command-handling code or
something.

[Matt Giuca, 2017/03/02 23:59:30]

None of the other places where IDC_BACKSPACE_BACK is enumerated seem
comment-friendly either (they're all big tables), except for the switch
statement where it's handled, and that leads you to the well-documented
NewBackShortcutBubble. I'll just delete this then.

 #define IDC_BACKSPACE_BACK              33010
 #define IDC_BACKSPACE_FORWARD           33011