Wake Lock API implementation (Chromium part)

content/browser/wake_lock/wake_lock_state.h

+// 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.
+
+#ifndef CONTENT_BROWSER_WAKE_LOCK_WAKE_LOCK_STATE_H_
+#define CONTENT_BROWSER_WAKE_LOCK_WAKE_LOCK_STATE_H_
+
+#include <set>
+
+#include "base/macros.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+class RenderFrameHost;
+
+// Encapsulates wake lock state decision logic for WebContents. Clients update
+// this object's state and read resulting lock status via |GetLockState()|.
+class CONTENT_EXPORT WakeLockState {
+ public:
+  WakeLockState();
+  ~WakeLockState();

[mlamouri (slow - plz ping), 2015/08/06 09:18:51]

Do you need the dtor if you make the class "final"? It might be required if it's
not considered trivial. Though, in that case, can you make it = default?

Same for the ctor above.

[alogvinov, 2015/08/11 13:06:43]

Making dtor = default gives "[chromium-style] Complex constructor has an inlined
body." error, ditto for the ctor. I believe the std::set member is what's making
this class complex.

+
+  void AddFrame(const RenderFrameHost* frame);
+  void RemoveFrame(const RenderFrameHost* frame);
+  void RemoveAllFrames();
+
+  bool GetLockState() const;

[mlamouri (slow - plz ping), 2015/08/06 09:18:51]

Hmm, that's a bit odd. Why not "HasFrame()"? I think it would be more explicit.

[alogvinov, 2015/08/11 13:06:43]

Done.

+
+ private:
+  typedef std::set<const RenderFrameHost*> FramesContainer;

[mlamouri (slow - plz ping), 2015/08/06 09:18:51]

nit: using FramesContainer = std::set<const RenderFrameHost*>;

[alogvinov, 2015/08/11 13:06:43]

Hm, I'd rather remove the typedef as it is private and the type alias is not
used anywhere else.

+  FramesContainer frames_requesting_lock_;
+
+  DISALLOW_COPY_AND_ASSIGN(WakeLockState);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_WAKE_LOCK_WAKE_LOCK_STATE_H_