ash: Add a feature flag for the Keyboard Shortcut Viewer mojo app

Default is disabled for now. Remove the old commandline switch.

[email protected]

Bug: 841020
Change-Id: Ie5df91612d6c976b0b7f056c7248dc92cee9be68
Reviewed-on: https://chromium-review.googlesource.com/1101505
Commit-Queue: Michael Wasserman <[email protected]>
Reviewed-by: James Cook <[email protected]>
Cr-Commit-Position: refs/heads/master@{#567425}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 6829206..31408c7 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -3531,6 +3531,11 @@
      flag_descriptions::kAshEnableKeyboardShortcutViewerDescription, kOsCrOS,
      FEATURE_VALUE_TYPE(ash::features::kKeyboardShortcutViewer)},
 
+    {"ash-keyboard-shortcut-viewer-app",
+     flag_descriptions::kAshKeyboardShortcutViewerAppName,
+     flag_descriptions::kAshKeyboardShortcutViewerAppDescription, kOsCrOS,
+     FEATURE_VALUE_TYPE(ash::features::kKeyboardShortcutViewerApp)},
+
     {"ash-disable-login-dim-and-blur",
      flag_descriptions::kAshDisableLoginDimAndBlurName,
      flag_descriptions::kAshDisableLoginDimAndBlurDescription, kOsCrOS,