Add chrome.searchEnginesPrivate API and Search Settings page.

chrome/common/extensions/api/_permission_features.json

Index: chrome/common/extensions/api/_permission_features.json
diff --git a/chrome/common/extensions/api/_permission_features.json b/chrome/common/extensions/api/_permission_features.json
index de15be244324bdc14c4839043c6798deeb81f2d4..5f32b7d08a31a1fb5bf529bb05280a24f2e2c919 100644
--- a/chrome/common/extensions/api/_permission_features.json
+++ b/chrome/common/extensions/api/_permission_features.json
@@ -869,6 +869,12 @@
     "extension_types": ["platform_app"],
     "location": "component"
   },
+  "searchEnginesPrivate": {
+    "channel": "trunk",
+    "extension_types": ["extension", "platform_app"],
+    "platforms": ["chromeos", "mac", "win", "linux"],
+    "whitelist": []
+  },
   "screensaver": {
     "channel": "stable",
     "extension_types": ["legacy_packaged_app", "hosted_app", "platform_app"]