Teach mojo_shell how to load http URLs

mojo/loader/loader.cc

+// Copyright (c) 2013 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 "base/message_loop/message_loop.h"
+#include "base/threading/thread.h"
+#include "mojo/loader/loader.h"
+#include "mojo/loader/url_request_context_getter.h"
+#include "net/url_request/url_fetcher.h"
+#include "net/url_request/url_fetcher_delegate.h"
+
+namespace mojo {
+namespace loader {
+
+namespace {
+
+class FetchDelegate : public net::URLFetcherDelegate {
+ public:
+  explicit FetchDelegate(Loader::Delegate* delegate)
+      : delegate_(delegate) {
+  }
+
+  virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
+
+ private:
+  Loader::Delegate* delegate_;
+};
+
+void FetchDelegate::OnURLFetchComplete(const net::URLFetcher* source) {
+  delegate_->DidCompleteLoad(source->GetURL());
+  delete this;
+}
+
+scoped_ptr<base::Thread> CreateIOThread(const char* name) {
+  scoped_ptr<base::Thread> thread(new base::Thread(name));
+  base::Thread::Options options;
+  options.message_loop_type = base::MessageLoop::TYPE_IO;
+  thread->StartWithOptions(options);
+  return thread.Pass();
+}
+
+}

[darin (slow to review), 2013/10/18 07:11:29]

nit: "}  // namespace"

[abarth-chromium, 2013/10/18 07:27:17]

Thanks.  My Chromium style is a bit rusty.  :)

+
+class Loader::Data {
+ public:
+  scoped_ptr<base::Thread> cache_thread;
+  scoped_refptr<URLRequestContextGetter> url_request_context_getter;
+};
+
+Loader::Loader(base::SingleThreadTaskRunner* network_runner,
+               base::FilePath base_path)
+    : data_(new Data()) {
+  data_->cache_thread = CreateIOThread("cache_thread");
+  data_->url_request_context_getter = new URLRequestContextGetter(
+      base_path, network_runner, data_->cache_thread->message_loop_proxy());
+}
+
+Loader::~Loader() {

[darin (slow to review), 2013/10/18 07:11:29]

what if Loader is destroyed before OnURLFetchComplete gets called? it seems you
could end up in a situation where FetchDelegate holds a junk pointer to a
Loader::Delegate.

Also, I think you need to put the fetcher in a scoped_ptr<net::URLFetcher>
member variable.  normally, this would be on the Loader class, and the Loader
class would implement URLFetcherDelegate. If you want to create an inner class
to hide those details, that's fine. Just make the Loader own the inner class
instance.

[abarth-chromium, 2013/10/18 07:27:17]

That's a good point.
Makes sense.  Will fix.

+}
+
+void Loader::Load(const GURL& app_url, Delegate* delegate) {
+  net::URLFetcher* fetcher = net::URLFetcher::Create(
+      app_url, net::URLFetcher::GET, new FetchDelegate(delegate));
+
+  fetcher->SetRequestContext(data_->url_request_context_getter.get());
+  fetcher->Start();
+}
+
+}  // namespace loader
+}  // namespace mojo