Convert PowerSaveBlockResourceThrottle to be client of WakeLock mojo service.

content/browser/loader/wake_lock_resource_throttle.h

+// 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.
+
+#ifndef CONTENT_BROWSER_LOADER_WAKE_LOCK_RESOURCE_THROTTLE_H_
+#define CONTENT_BROWSER_LOADER_WAKE_LOCK_RESOURCE_THROTTLE_H_
+
+#include <memory>
+#include <string>
+
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "base/timer/timer.h"
+#include "content/public/browser/resource_throttle.h"
+#include "device/wake_lock/public/interfaces/wake_lock_service.mojom.h"
+
+namespace content {
+
+// This ResourceThrottle holds wake lock until large upload request finishes.
+class WakeLockResourceThrottle : public ResourceThrottle {
+ public:
+  WakeLockResourceThrottle(const std::string& host);
+  ~WakeLockResourceThrottle() override;
+
+  // ResourceThrottle overrides:
+  void WillStartRequest(bool* defer) override;
+  void WillProcessResponse(bool* defer) override;
+  const char* GetNameForLogging() const override;
+
+ private:
+  void RequestWakeLock();
+
+  const std::string host_;
+  base::OneShotTimer timer_;
+
+  // Destruction of wake_lock_ will trigger

[Charlie Harrison, 2017/05/18 16:43:49]

Suggested rephrasing:
Destruction of wake_lock_ will trigger WakeLockServiceImpl::OnConnection error
on the service side, so there is no need to call CancelWakeLock() in the
destructor.

[ke.he, 2017/05/19 03:35:52]

Done.

+  // WakeLockServicImpl::OnConnectionError in remote Device Service side, in
+  // which the wake lock is well updated. So no need to call CancelWakeLock() in
+  // destructor of this class.
+  device::mojom::WakeLockServicePtr wake_lock_;
+
+  DISALLOW_COPY_AND_ASSIGN(WakeLockResourceThrottle);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_WAKE_LOCK_RESOURCE_THROTTLE_H_