Convert PowerSaveBlockResourceThrottle to be client of WakeLock mojo service.

content/browser/loader/wake_lock_resource_throttle.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.

[Charlie Harrison, 2017/05/18 13:56:42]

Copyright 2017

[ke.he, 2017/05/18 14:13:11]

Actually this file is renamed from the original
power_save_block_resource_throttle.cc, I think maybe we would keep the "2013"
here?  Same in the ".h" file.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/loader/wake_lock_resource_throttle.h"
+
+#include "content/browser/service_manager/service_manager_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "device/wake_lock/public/interfaces/wake_lock_provider.mojom.h"
+#include "services/device/public/interfaces/constants.mojom.h"
+#include "services/service_manager/public/cpp/connector.h"
+
+namespace content {
+
+namespace {
+
+const int kWakeLockDelaySeconds = 30;
+
+}  // namespace
+
+WakeLockResourceThrottle::WakeLockResourceThrottle(const std::string& host)
+    : host_(host) {}
+
+WakeLockResourceThrottle::~WakeLockResourceThrottle() {}
+
+void WakeLockResourceThrottle::WillStartRequest(bool* defer) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  // Delay wake lock activation to dismiss small requests.
+  timer_.Start(FROM_HERE, base::TimeDelta::FromSeconds(kWakeLockDelaySeconds),
+               this, &WakeLockResourceThrottle::ActivateWakeLock);
+}
+
+void WakeLockResourceThrottle::WillProcessResponse(bool* defer) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  // Cancel wake lock after request finishes.
+  if (wake_lock_)
+    wake_lock_->CancelWakeLock();
+
+  timer_.Stop();
+}
+
+const char* WakeLockResourceThrottle::GetNameForLogging() const {
+  return "WakeLockResourceThrottle";
+}
+
+void WakeLockResourceThrottle::ActivateWakeLock() {

[Charlie Harrison, 2017/05/18 14:46:17]

Maybe s/Activate/Request ?

[ke.he, 2017/05/18 15:35:15]

Done.

+  DCHECK_CURRENTLY_ON(BrowserThread::IO);

[ke.he, 2017/05/18 13:40:09]

I think the original PowerSaveBlockResourceThrottle always runs in IO thread,
right?

[Charlie Harrison, 2017/05/18 13:56:42]

Yep, all ResourceThrottles run on the IO thread.

[ke.he, 2017/05/18 14:13:11]

Thanks!

+  DCHECK(!wake_lock_);

[ke.he, 2017/05/18 13:40:09]

This ActivateWakeLock() will never be called twice, right? So I DCHECK the
wake_lock_ be initiallized only once.

[Charlie Harrison, 2017/05/18 13:56:42]

Yep, WillStartRequest should only be called once.

+
+  service_manager::Connector* connector =
+      ServiceManagerContext::GetConnectorForIOThread();
+  // |connector| might be nullptr in some testing contexts, in which the
+  // service manager connection isn't initialized.
+  if (connector) {
+    device::mojom::WakeLockProviderPtr wake_lock_provider;
+    connector->BindInterface(device::mojom::kServiceName,
+                             mojo::MakeRequest(&wake_lock_provider));

[Charlie Harrison, 2017/05/18 14:46:17]

Do we need to include mojo/public/cpp/bindings/interface_request.h ?

[ke.he, 2017/05/18 15:35:15]

Done.

+    wake_lock_provider->GetWakeLockWithoutContext(
+        device::mojom::WakeLockType::PreventAppSuspension,
+        device::mojom::WakeLockReason::ReasonOther,
+        "Uploading data to " + host_, mojo::MakeRequest(&wake_lock_));
+
+    wake_lock_->RequestWakeLock();
+  }
+}
+
+}  // namespace content