[New Tab Page] Change the mechanism to intercept online NTP errors

chrome/browser/ui/search/new_tab_page_interceptor_service.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/ui/search/new_tab_page_interceptor_service.h"
+
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/search/search.h"
+#include "chrome/browser/ui/search/new_tab_page_interceptor.h"
+#include "content/public/browser/browser_thread.h"
+
+NewTabPageInterceptorService::NewTabPageInterceptorService(Profile* profile)
+    : profile_(profile) {
+  DCHECK(profile_);
+}
+
+NewTabPageInterceptorService::~NewTabPageInterceptorService() {
+}
+
+void NewTabPageInterceptorService::UpdateDefaultSearchProvider(
+    const GURL& new_tab_page_url) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,

[mmenke, 2015/01/15 22:35:30]

Should include base/location.h for FROM_HERE.  Believe browser_thread currently
includes it, but shouldn't depend on that.

[Mathieu, 2015/01/22 19:21:59]

Done.

+      base::Bind(&NewTabPageInterceptor::SetNewTabPageURL, interceptor_,
+                 new_tab_page_url));
+}
+
+scoped_ptr<net::URLRequestInterceptor>
+NewTabPageInterceptorService::CreateInterceptor() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  scoped_ptr<NewTabPageInterceptor> interceptor(
+      new NewTabPageInterceptor(chrome::GetNewTabPageURL(profile_)));
+  interceptor_ = interceptor->GetWeakPtr();
+  return interceptor.Pass();
+}