Make some updates to extension iconography.

chrome/test/data/extensions/context_menus/icons/manifest.json

Index: chrome/test/data/extensions/context_menus/icons/manifest.json
diff --git a/chrome/test/data/extensions/context_menus/icons/manifest.json b/chrome/test/data/extensions/context_menus/icons/manifest.json
new file mode 100644
index 0000000000000000000000000000000000000000..4759a52760dd67c6e803171b6689438ff5434d7a
--- /dev/null
+++ b/chrome/test/data/extensions/context_menus/icons/manifest.json
@@ -0,0 +1,15 @@
+{
+  "name": "Context Menus Sample",
+  "description": "Shows some of the features of the Context Menus API",
+  "version": "0.6",
+  "permissions": ["contextMenus"],
+  "background": {
+    "scripts": ["sample.js"]
+  },
+  "icons": {
+    "16": "16.png",
+    "24": "24.png",
+    "32": "32.png"
+  },
+  "manifest_version": 2
+}