Remove implementation of Panels on OSes other than ChromeOS.

chrome/test/data/panels/context_menu/manifest.json

Index: chrome/test/data/panels/context_menu/manifest.json
diff --git a/chrome/test/data/panels/context_menu/manifest.json b/chrome/test/data/panels/context_menu/manifest.json
deleted file mode 100644
index e44c8e3db243a5a52e2bdade7e687044b642e128..0000000000000000000000000000000000000000
--- a/chrome/test/data/panels/context_menu/manifest.json
+++ /dev/null
@@ -1,10 +0,0 @@
-{
-  "name": "Extension that creates a panel and custom context menu item.",
-  "version": "1",
-  "manifest_version": 2,
-  "description": "Used to verify panels can create custom context menu items.",
-  "background": {
-    "scripts": ["test.js"]
-  },
-  "permissions": ["contextMenus", "tabs"]
-}