Track the active ExtensionKeybindingRegistry and make it available to EventRewriter.

chrome/test/data/extensions/api_test/keybinding/chromeos_conversions/manifest.json

Index: chrome/test/data/extensions/api_test/keybinding/chromeos_conversions/manifest.json
diff --git a/chrome/test/data/extensions/api_test/keybinding/chromeos_conversions/manifest.json b/chrome/test/data/extensions/api_test/keybinding/chromeos_conversions/manifest.json
new file mode 100644
index 0000000000000000000000000000000000000000..21525516213b0eac86f9db616ba843db4dfb7588
--- /dev/null
+++ b/chrome/test/data/extensions/api_test/keybinding/chromeos_conversions/manifest.json
@@ -0,0 +1,35 @@
+{
+  "name": "An extension to test shortcuts propagation",
+  "version": "1.0",
+  "manifest_version": 2,
+  "background": {
+    "scripts": ["background.js"]
+  },
+  "permissions": [ "tabs" ],
+  "commands": {
+    "Search-Shift-Left": {
+      "description": "Test non-conversion of this key",
+      "suggested_key": {
+        "chromeos": "Search+Shift+Left"
+      }
+    },
+    "Search-Shift-Up": {
+      "description": "Test non-conversion of this key",
+      "suggested_key": {
+        "chromeos": "Search+Shift+Up"
+      }
+    },
+    "Search-Shift-Right": {
+      "description": "Test non-conversion of this key",
+      "suggested_key": {
+        "chromeos": "Search+Shift+Right"
+      }
+    },
+    "Search-Shift-Down": {
+      "description": "Test non-conversion of this key",
+      "suggested_key": {
+        "chromeos": "Search+Shift+Down"
+      }
+    }
+  }
+}