[Contextual Search] Add Mojo-enabled API component.

chrome/browser/search/contextual_search_api_controller.cc

+// Copyright 2015 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/search/contextual_search_api_controller.h"
+
+#include "content/public/browser/render_process_host.h"
+
+// static
+ContextualSearchApiController* ContextualSearchApiController::GetInstance() {
+  return base::Singleton<ContextualSearchApiController>::get();
+}
+
+ContextualSearchApiController::ContextualSearchApiController() {}
+
+ContextualSearchApiController::~ContextualSearchApiController() {}
+
+void ContextualSearchApiController::AddProcessId(int process_id) {
+  process_ids_.insert(process_id);
+}
+
+void ContextualSearchApiController::RemoveProcessId(int process_id) {
+  process_ids_.erase(process_id);
+}
+
+bool ContextualSearchApiController::IsContextualSearchProcessId(
+    int process_id) const {
+  return process_ids_.find(process_id) != process_ids_.end();
+}