First pass at experimental omnibox API. There are plenty of rough edges and

chrome/common/extensions/extension.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/extensions/extension.h"
 
 #include <algorithm>
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
@@ skipping 1438 matching lines @@
       chrome_url_overrides_[page] = GetResourceURL(val);
     }
 
     // An extension may override at most one page.
     if (overrides->size() > 1) {
       *error = errors::kMultipleOverrides;
       return false;
     }
   }
 
+  if (source.HasKey(keys::kOmniboxKeyword)) {
+    if (!source.GetString(keys::kOmniboxKeyword, &omnibox_keyword_) ||
+        omnibox_keyword_.empty()) {
+      *error = errors::kInvalidOmniboxKeyword;
+      return false;
+    }
+    if (!HasApiPermission(Extension::kExperimentalPermission)) {
+      *error = errors::kOmniboxExperimental;
+      return false;
+    }
+  }
+
   if (!CheckAppsAreEnabled(manifest_value_.get(), error) ||
       !LoadWebContentEnabled(manifest_value_.get(), error) ||
       !LoadWebOrigin(manifest_value_.get(), error) ||
       !LoadWebPaths(manifest_value_.get(), error) ||
       !LoadLaunchURL(manifest_value_.get(), error) ||
       !LoadLaunchContainer(manifest_value_.get(), error) ||
       !LoadLaunchFullscreen(manifest_value_.get(), error)) {
     return false;
   }
 
@@ skipping 229 matching lines @@
         } else {
           return false;
         }
       } else {
         return true;
       }
     }
   }
   return false;
 }