[Contextual Search] Add Mojo-enabled API component.

chrome/browser/search/contextual_search_service.cc

Index: chrome/browser/search/contextual_search_service.cc
diff --git a/chrome/browser/search/contextual_search_service.cc b/chrome/browser/search/contextual_search_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..949d22190747c2a77369125572f00fcd597d00fb
--- /dev/null
+++ b/chrome/browser/search/contextual_search_service.cc
@@ -0,0 +1,54 @@
+// 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_service.h"
+
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_types.h"
+#include "content/public/browser/render_process_host.h"
+
+namespace {
+  int kInvalidProcessId = -1;
+}
+
+// static
+ContextualSearchService* ContextualSearchService::GetInstance() {
+  return base::Singleton<ContextualSearchService>::get();
+}
+
+ContextualSearchService::ContextualSearchService()
+  : process_id_(kInvalidProcessId) {
+  registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_TERMINATED,
+                 content::NotificationService::AllSources());
+}
+
+ContextualSearchService::~ContextualSearchService() {}
+
+void ContextualSearchService::SetContextualSearchProcess(int process_id) {
+  process_id_ = process_id;
+}
+
+bool ContextualSearchService::IsContextualSearchProcess(int process_id) const {
+  return process_id == process_id_;
+}
+
+void ContextualSearchService::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  switch (type) {
+    case content::NOTIFICATION_RENDERER_PROCESS_TERMINATED:
+      OnRendererProcessTerminated(
+          content::Source<content::RenderProcessHost>(source)->GetID());
+      break;
+    default:
+      NOTREACHED()
+          << "Unexpected notification type in ContextualSearchService.";
+  }
+}
+
+void ContextualSearchService::OnRendererProcessTerminated(int process_id) {
+  if (process_id == process_id_)
+    process_id_ = kInvalidProcessId;
+}