Make platform apps use and require a different container ("shell" instead of "panel")

chrome/browser/extensions/extension_prefs.cc

Index: chrome/browser/extensions/extension_prefs.cc
diff --git a/chrome/browser/extensions/extension_prefs.cc b/chrome/browser/extensions/extension_prefs.cc
index ebe337cc0b60403f3c82af43d9fae8d2f6495a9b..e8eed1812b0d35734965398e144ff11c24b6bf86 100644
--- a/chrome/browser/extensions/extension_prefs.cc
+++ b/chrome/browser/extensions/extension_prefs.cc
@@ -973,10 +973,11 @@ extension_misc::LaunchContainer ExtensionPrefs::GetLaunchContainer(
 
   extension_misc::LaunchContainer result = kInvalidLaunchContainer;
 
-  if (manifest_launch_container == extension_misc::LAUNCH_PANEL) {
-    // Apps with app.launch.container = 'panel' should always
-    // open in a panel.
-    result = extension_misc::LAUNCH_PANEL;
+  if (manifest_launch_container == extension_misc::LAUNCH_PANEL ||
+      manifest_launch_container == extension_misc::LAUNCH_SHELL) {
+    // Apps with app.launch.container = 'panel' or 'shell' should always respect
+    // the manifest setting.
+    result = manifest_launch_container;
 
   } else if (manifest_launch_container == extension_misc::LAUNCH_TAB) {
     // Look for prefs that indicate the user's choice of launch