Switch platform apps from a declarative launch container to handling an onLaunched event.

chrome/browser/extensions/extension_apitest.h

Index: chrome/browser/extensions/extension_apitest.h
diff --git a/chrome/browser/extensions/extension_apitest.h b/chrome/browser/extensions/extension_apitest.h
index 8d98fad2333accd2d49795c1ecf9a099382a40d0..28ec8b45a5226d8fb1dfcb2bae20bf61ad070724 100644
--- a/chrome/browser/extensions/extension_apitest.h
+++ b/chrome/browser/extensions/extension_apitest.h
@@ -48,8 +48,8 @@ class ExtensionApiTest : public ExtensionBrowserTest {
     // Loads the extension with location COMPONENT.
     kFlagLoadAsComponent = 1 << 3,
 
-    // Launch the extension in a platform app shell.
-    kFlagLaunchAppShell = 1 << 4
+    // Launch the extension as a platform app.
+    kFlagLaunchPlatformApp = 1 << 4
   };
 
   ExtensionApiTest();