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

chrome/browser/extensions/extension_omnibox_api.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/browser/extensions/extension_omnibox_api.h"
+
+#include "base/json/json_writer.h"
+#include "base/string_util.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/extension_message_service.h"
+#include "chrome/browser/profile.h"
+#include "chrome/common/notification_service.h"
+
+namespace events {
+const char kOnInputChanged[] = "experimental.omnibox.onInputChanged/";
+const char kOnInputEntered[] = "experimental.omnibox.onInputEntered/";
+};  // namespace events
+
+// static
+bool ExtensionOmniboxEventRouter::OnInputChanged(
+    Profile* profile, const std::string& extension_id,
+    const std::string& input, int suggest_id) {
+  std::string event_name = events::kOnInputChanged + extension_id;
+  if (!profile->GetExtensionMessageService()->HasEventListener(event_name))
+    return false;
+
+  ListValue args;
+  args.Set(0, Value::CreateStringValue(input));
+  args.Set(1, Value::CreateIntegerValue(suggest_id));
+  std::string json_args;
+  base::JSONWriter::Write(&args, false, &json_args);
+
+  profile->GetExtensionMessageService()->DispatchEventToRenderers(
+      event_name, json_args, profile->IsOffTheRecord(), GURL());
+  return true;
+}
+
+// static
+void ExtensionOmniboxEventRouter::OnInputEntered(
+    Profile* profile, const std::string& extension_id,
+    const std::string& input) {
+  std::string event_name = events::kOnInputEntered + extension_id;
+
+  ListValue args;
+  args.Set(0, Value::CreateStringValue(input));
+  std::string json_args;
+  base::JSONWriter::Write(&args, false, &json_args);
+
+  profile->GetExtensionMessageService()->DispatchEventToRenderers(
+      event_name, json_args, profile->IsOffTheRecord(), GURL());
+}
+
+bool OmniboxSendSuggestionsFunction::RunImpl() {
+  int request_id;
+  ListValue* suggestions_value;
+  EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &request_id));
+  EXTENSION_FUNCTION_VALIDATE(args_->GetList(1, &suggestions_value));
+
+  ExtensionOmniboxSuggestions details(request_id, suggestions_value);
+  NotificationService::current()->Notify(
+      NotificationType::EXTENSION_OMNIBOX_SUGGESTIONS_READY,
+      Source<Profile>(profile_),
+      Details<ExtensionOmniboxSuggestions>(&details));
+
+  return true;
+}
+