Enable devtools via context menu in platform apps and popup extensions.

content/public/browser/notification_types.h

Index: content/public/browser/notification_types.h
diff --git a/content/public/browser/notification_types.h b/content/public/browser/notification_types.h
index 363df21a7d4ce5517eb36472e4c29d71f2d86a1b..9e1ff3a2e7c6caad8fb0f72d4715ed4ce7c35278 100644
--- a/content/public/browser/notification_types.h
+++ b/content/public/browser/notification_types.h
@@ -191,6 +191,10 @@ enum NotificationType {
   //  The source and details are unspecified.
   NOTIFICATION_APP_EXITING,
 
+  // Indicates that a devtools window is opening. The source is the
+  // content::BrowserContext* and the details is the inspected RenderViewHost*.
+  NOTIFICATION_DEVTOOLS_WINDOW_OPENING,
+
   // Indicates that a devtools window is closing. The source is the
   // content::BrowserContext* and the details is the inspected RenderViewHost*.
   NOTIFICATION_DEVTOOLS_WINDOW_CLOSING,