bluetooth: Disconnect if the page becomes hidden or is closed.

third_party/WebKit/Source/modules/bluetooth/BluetoothGATTRemoteServer.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 BluetoothGATTRemoteServer_h
 #define BluetoothGATTRemoteServer_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "bindings/modules/v8/UnionTypesModules.h"
+#include "core/dom/ActiveDOMObject.h"
+#include "core/page/PageLifecycleObserver.h"
 #include "platform/heap/Heap.h"
 #include "public/platform/modules/bluetooth/WebBluetoothGATTRemoteServer.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class ScriptPromise;
 class ScriptPromiseResolver;
 class ScriptState;
 
 // BluetoothGATTRemoteServer provides a way to interact with a connected bluetooth peripheral.
 //
 // Callbacks providing WebBluetoothGATTRemoteServer objects are handled by
 // CallbackPromiseAdapter templatized with this class. See this class's
 // "Interface required by CallbackPromiseAdapter" section and the
 // CallbackPromiseAdapter class comments.
 class BluetoothGATTRemoteServer final
     : public GarbageCollectedFinalized<BluetoothGATTRemoteServer>
+    , public ActiveDOMObject
+    , public PageLifecycleObserver
     , public ScriptWrappable {
+    USING_PRE_FINALIZER(BluetoothGATTRemoteServer, dispose);
     DEFINE_WRAPPERTYPEINFO();
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(BluetoothGATTRemoteServer);
 public:
-    BluetoothGATTRemoteServer(PassOwnPtr<WebBluetoothGATTRemoteServer>);
+    BluetoothGATTRemoteServer(ExecutionContext*, PassOwnPtr<WebBluetoothGATTRemoteServer>);
 
     // Interface required by CallbackPromiseAdapter:
     using WebType = OwnPtr<WebBluetoothGATTRemoteServer>;
     static BluetoothGATTRemoteServer* take(ScriptPromiseResolver*, PassOwnPtr<WebBluetoothGATTRemoteServer>);
 
+    // We should disconnect from the device in all of the following cases:
+    // 1. When the object gets GarbageCollected e.g. it went out of scope.
+    // dispose() is called in this case.
+    // 2. When the parent document gets detached e.g. reloading a page.
+    // stop() is called in this case.
+    // 3. For now (https://crbug.com/579746), when the tab is no longer in the
+    // foreground e.g. change tabs.
+    // pageVisibilityChanged() is called in this case.
+    // TODO(ortuno): Users should be able to turn on notifications listen for
+    // events on navigator.bluetooth and still remain connected even if the
+    // BluetoothGATTRemoteServer object is garbage collected.
+    // TODO(ortuno): Allow connections when the tab is in the background.
+    // This is a short term solution instead of implementing a tab indicator
+    // for bluetooth connections.
+    // https://crbug.com/579746

[Jeffrey Yasskin, 2016/01/22 21:59:02]

You can probably remove this line.

[ortuno, 2016/01/22 22:18:14]

Done.

+
+    // USING_PRE_FINALIZER interface.
+    // Called before the object gets garbage collected.
+    void dispose();
+
+    // ActiveDOMObject interface.
+    void stop() override;
+
+    // PageLifecycleObserver interface.
+    void pageVisibilityChanged() override;
+
+    void disconnectIfConnected();
+
     // Interface required by Garbage Collectoin:
-    DEFINE_INLINE_TRACE() { }
+    DECLARE_VIRTUAL_TRACE();
 
     // IDL exposed interface:
     bool connected() { return m_webGATT->connected; }
     void disconnect(ScriptState*);
     ScriptPromise getPrimaryService(ScriptState*, const StringOrUnsignedLong& service, ExceptionState&);
 
 private:
     OwnPtr<WebBluetoothGATTRemoteServer> m_webGATT;
 };
 
 } // namespace blink
 
 #endif // BluetoothDevice_h