Add mojo package manager skeleton.

mojo/tools/package_manager/package_fetcher.cc

Index: mojo/tools/package_manager/package_fetcher.cc
diff --git a/mojo/tools/package_manager/package_fetcher.cc b/mojo/tools/package_manager/package_fetcher.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b5a47e53fe2482d726cfea5173ecedca9d0816e4
--- /dev/null
+++ b/mojo/tools/package_manager/package_fetcher.cc
@@ -0,0 +1,96 @@
+// Copyright 2014 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 "mojo/tools/package_manager/package_fetcher.h"
+
+#include "base/bind.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "mojo/services/public/interfaces/network/url_loader.mojom.h"
+
+namespace mojo {
+
+PackageFetcher::PackageFetcher(NetworkService* network_service,
+                               PackageFetcherDelegate* delegate,
+                               const GURL& url)
+    : delegate_(delegate),
+      url_(url) {
+  network_service->CreateURLLoader(Get(&loader_));
+
+  URLRequestPtr request(URLRequest::New());
+  request->url = url.spec();
+  request->auto_follow_redirects = true;
+
+  loader_->Start(request.Pass(),
+                 base::Bind(&PackageFetcher::OnReceivedResponse,
+                            base::Unretained(this)));
+}
+
+PackageFetcher::~PackageFetcher() {
+}
+
+void PackageFetcher::OnReceivedResponse(URLResponsePtr response) {
+  if (response->error) {
+    printf("Got error %d (%s) for %s\n",
+           response->error->code,
+           response->error->description.get().c_str(),
+           url_.spec().c_str());
+    delegate_->FetchFailed(url_);
+    return;
+  }
+
+  if (!base::CreateTemporaryFile(&output_file_name_)) {
+    delegate_->FetchFailed(url_);
+    return;
+  }
+  output_file_.Initialize(output_file_name_,
+      base::File::FLAG_CREATE_ALWAYS | base::File::FLAG_WRITE);
+  if (!output_file_.IsValid()) {
+    base::DeleteFile(output_file_name_, false);
+    delegate_->FetchFailed(url_);
+    // Danger: may be deleted now.
+    return;
+  }
+
+  body_ = response->body.Pass();
+  ReadData(MOJO_RESULT_OK);
+  // Danger: may be deleted now.
+}
+
+void PackageFetcher::ReadData(MojoResult) {
+  char buf[4096];
+  uint32_t num_bytes = sizeof(buf);
+  MojoResult result = ReadDataRaw(body_.get(), buf, &num_bytes,
+                                  MOJO_READ_DATA_FLAG_NONE);
+  if (result == MOJO_RESULT_SHOULD_WAIT) {
+    WaitToReadMore();
+  } else if (result == MOJO_RESULT_OK) {
+    if (output_file_.WriteAtCurrentPos(buf, num_bytes) !=
+        static_cast<int>(num_bytes)) {
+      // Clean up the output file.
+      output_file_.Close();
+      base::DeleteFile(output_file_name_, false);
+
+      delegate_->FetchFailed(url_);
+      // Danger: may be deleted now.
+      return;
+    }
+    WaitToReadMore();
+  } else if (result == MOJO_RESULT_FAILED_PRECONDITION) {
+    // Done.
+    output_file_.Close();
+    delegate_->FetchSucceeded(url_, output_file_name_);
+    // Danger: may be deleted now.
+  }
+}
+
+void PackageFetcher::WaitToReadMore() {
+  handle_watcher_.Start(
+      body_.get(),
+      MOJO_HANDLE_SIGNAL_READABLE,
+      MOJO_DEADLINE_INDEFINITE,
+      base::Bind(&PackageFetcher::ReadData, base::Unretained(this)));
+}
+
+}  // namespace mojo