chromeos: Add constants for showing in-session auth dialog dev overlay

This enables developing the dialog and related functionalities without
having to worry too much about the view itself.

Bug: b:156258540
Change-Id: If0dd36671742d9f2b3c576ef3d4f3a52577356ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2298586
Commit-Queue: Yicheng Li <yichengli@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791347}

chromeos/constants/chromeos_switches.cc

@@ -518,6 +518,11 @@ const char kHideAndroidFilesInFilesApp[] = "hide-android-files-in-files-app";
 // "/usr/share/chromeos-assets/regulatory_labels/".
 const char kRegulatoryLabelDir[] = "regulatory-label-dir";
 
+// If true, the debug view overlay will be shown for the in-session
+// authentication dialog. This enables development of the dialog.
+// TODO(yichenli): Remove this after the feature is released.
+const char kShowAuthDialogDevOverlay[] = "show-auth-dialog-dev-overlay";
+
 // If true, the developer tool overlay will be shown for the login/lock screen.
 // This makes it easier to test layout logic.
 const char kShowLoginDevOverlay[] = "show-login-dev-overlay";

chromeos/constants/chromeos_switches.h

@@ -203,6 +203,8 @@ COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kShelfHoverPreviews[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kShelfHotseat[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const char kShowAndroidFilesInFilesApp[];
+COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
+extern const char kShowAuthDialogDevOverlay[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kShowLoginDevOverlay[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kShowOobeDevOverlay[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)