Close USB device connections when the page is hidden.

third_party/WebKit/Source/modules/webusb/USBDevice.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 USBDevice_h
 #define USBDevice_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "bindings/modules/v8/UnionTypesModules.h"
 #include "core/dom/ContextLifecycleObserver.h"
+#include "core/dom/Document.h"
+#include "core/page/PageLifecycleObserver.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/modules/webusb/WebUSBDevice.h"
 #include "public/platform/modules/webusb/WebUSBDeviceInfo.h"
 #include "wtf/BitVector.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class ScriptPromiseResolver;
 class ScriptState;
 class USBConfiguration;
 class USBControlTransferParameters;
 
 class USBDevice
     : public GarbageCollectedFinalized<USBDevice>
     , public ContextLifecycleObserver
-    , public ScriptWrappable {
+    , public ScriptWrappable
+    , public PageLifecycleObserver {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(USBDevice);
     DEFINE_WRAPPERTYPEINFO();
 public:
     using WebType = OwnPtr<WebUSBDevice>;
 
     static USBDevice* create(PassOwnPtr<WebUSBDevice> device, ExecutionContext* context)
     {
         return new USBDevice(device, context);
     }
 
@@ skipping 39 matching lines @@
     ScriptPromise controlTransferIn(ScriptState*, const USBControlTransferParameters& setup, unsigned length);
     ScriptPromise controlTransferOut(ScriptState*, const USBControlTransferParameters& setup);
     ScriptPromise controlTransferOut(ScriptState*, const USBControlTransferParameters& setup, const ArrayBufferOrArrayBufferView& data);
     ScriptPromise clearHalt(ScriptState*, String direction, uint8_t endpointNumber);
     ScriptPromise transferIn(ScriptState*, uint8_t endpointNumber, unsigned length);
     ScriptPromise transferOut(ScriptState*, uint8_t endpointNumber, const ArrayBufferOrArrayBufferView& data);
     ScriptPromise isochronousTransferIn(ScriptState*, uint8_t endpointNumber, Vector<unsigned> packetLengths);
     ScriptPromise isochronousTransferOut(ScriptState*, uint8_t endpointNumber, const ArrayBufferOrArrayBufferView& data, Vector<unsigned> packetLengths);
     ScriptPromise reset(ScriptState*);
 
+    // ContextLifecycleObserver interface.
     void contextDestroyed() override;
 
+    // PageLifecycleObserver interface.
+    void pageVisibilityChanged() override;
+
     DECLARE_TRACE();
 
 private:
     int findConfigurationIndex(uint8_t configurationValue) const;
     int findInterfaceIndex(uint8_t interfaceNumber) const;
     int findAlternateIndex(size_t interfaceIndex, uint8_t alternateSetting) const;
+    bool ensurePageVisible(ScriptPromiseResolver*) const;
     bool ensureNoDeviceOrInterfaceChangeInProgress(ScriptPromiseResolver*) const;
     bool ensureDeviceConfigured(ScriptPromiseResolver*) const;
     bool ensureInterfaceClaimed(uint8_t interfaceNumber, ScriptPromiseResolver*) const;
     bool ensureEndpointAvailable(bool inTransfer, uint8_t endpointNumber, ScriptPromiseResolver*) const;
     bool anyInterfaceChangeInProgress() const;
 
     OwnPtr<WebUSBDevice> m_device;
     bool m_opened;
     bool m_deviceStateChangeInProgress;
     int m_configurationIndex;
     WTF::BitVector m_claimedInterfaces;
     WTF::BitVector m_interfaceStateChangeInProgress;
     WTF::Vector<size_t> m_selectedAlternates;
 };
 
 } // namespace blink
 
 #endif // USBDevice_h