Implement <webview>.addContentScript/removeContentScript API [2]

extensions/browser/guest_view/web_view/web_ui/web_ui_url_fetcher.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 "extensions/browser/guest_view/web_view/web_ui/web_ui_url_fetcher.h"
+
+#include "content/public/browser/browser_context.h"
+#include "content/public/common/url_fetcher.h"

[Devlin, 2015/04/24 17:50:59]

Why is this include needed?

[Xi Han, 2015/04/24 18:28:54]

Removed.

+#include "net/base/load_flags.h"
+#include "net/url_request/url_fetcher.h"
+
+WebUIURLFetcher::WebUIURLFetcher(content::BrowserContext* context,
+                                 int render_process_id,
+                                 int render_view_id,
+                                 const GURL& url,
+                                 const WebUILoadFileCallback& callback)
+    : context_(context),
+      render_process_id_(render_process_id),
+      render_view_id_(render_view_id),
+      url_(url),
+      callback_(callback) {
+}
+
+WebUIURLFetcher::~WebUIURLFetcher() {
+}
+
+void WebUIURLFetcher::Start() {
+  fetcher_.reset(net::URLFetcher::Create(url_, net::URLFetcher::GET, this));
+  fetcher_->SetRequestContext(context_->GetRequestContext());
+  fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES);
+
+  content::AssociateURLFetcherWithRenderFrame(
+      fetcher_.get(), url_, render_process_id_, render_view_id_);
+  fetcher_->Start();
+}
+
+void WebUIURLFetcher::OnURLFetchComplete(const net::URLFetcher* source) {
+  CHECK_EQ(fetcher_.get(), source);
+
+  std::string data;
+  bool result = false;
+  if (fetcher_->GetStatus().status() == net::URLRequestStatus::SUCCESS) {
+    result = fetcher_->GetResponseAsString(&data);
+    DCHECK(result);
+  }
+  fetcher_.reset();
+  auto callback_cache = callback_;

[Devlin, 2015/04/24 17:50:59]

A quick comment on why we do this would be good.
// We cache the callback and reset it so that any references stored within it
are destroyed at the end of the method.

[Xi Han, 2015/04/24 18:28:54]

Done.

+  callback_.Reset();
+  callback_cache.Run(result, data);
+}