Clear Document::m_frame after dispatching ContextLifecycleObesrver::contextDestroyed

Bluetooth needs to use document->frame() in ContextLifecycleObesrver::contextDestroyed().
Hence this CL moves m_frame=nullptr to after dispatching contextDestroyed().

See https://groups.google.com/a/chromium.org/d/topic/blink-dev/sfpRQc4LB_I/discussion for more motivation of this CL.

BUG=610176

Review-Url: https://codereview.chromium.org/2362173002
Cr-Commit-Position: refs/heads/master@{#420588}

third_party/WebKit/Source/core/dom/Document.cpp

@@ -2270,13 +2270,6 @@ void Document::shutdown()
     m_timers.setTimerTaskRunner(
         Platform::current()->currentThread()->scheduler()->timerTaskRunner()->clone());
 
-    // This is required, as our LocalFrame might delete itself as soon as it detaches
-    // us. However, this violates Node::detachLayoutTree() semantics, as it's never
-    // possible to re-attach. Eventually Document::detachLayoutTree() should be renamed,
-    // or this setting of the frame to 0 could be made explicit in each of the
-    // callers of Document::detachLayoutTree().
-    m_frame = nullptr;
-
     if (m_mediaQueryMatcher)
         m_mediaQueryMatcher->documentDetached();
 
@@ -2289,6 +2282,13 @@ void Document::shutdown()
     // a contextDestroyed() notification. This can happen for a document
     // created by DOMImplementation::createDocument().
     ExecutionContext::notifyContextDestroyed();
+
+    // This is required, as our LocalFrame might delete itself as soon as it detaches
+    // us. However, this violates Node::detachLayoutTree() semantics, as it's never
+    // possible to re-attach. Eventually Document::detachLayoutTree() should be renamed,
+    // or this setting of the frame to 0 could be made explicit in each of the
+    // callers of Document::detachLayoutTree().
+    m_frame = nullptr;
 }
 
 void Document::removeAllEventListeners()

third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.cpp

@@ -18,7 +18,7 @@
 namespace blink {
 
 BluetoothDevice::BluetoothDevice(ExecutionContext* context, std::unique_ptr<WebBluetoothDeviceInit> webDevice)
-    : ActiveDOMObject(context)
+    : ContextLifecycleObserver(context)
     , m_webDevice(std::move(webDevice))
     , m_gatt(BluetoothRemoteGATTServer::create(this))
 {
@@ -29,9 +29,7 @@ BluetoothDevice::BluetoothDevice(ExecutionContext* context, std::unique_ptr<WebB
 BluetoothDevice* BluetoothDevice::take(ScriptPromiseResolver* resolver, std::unique_ptr<WebBluetoothDeviceInit> webDevice)
 {
     ASSERT(webDevice);
-    BluetoothDevice* device = new BluetoothDevice(resolver->getExecutionContext(), std::move(webDevice));
-    device->suspendIfNeeded();
-    return device;
+    return new BluetoothDevice(resolver->getExecutionContext(), std::move(webDevice));
 }
 
 void BluetoothDevice::dispose()
@@ -39,7 +37,7 @@ void BluetoothDevice::dispose()
     disconnectGATTIfConnected();
 }
 
-void BluetoothDevice::stop()
+void BluetoothDevice::contextDestroyed()
 {
     disconnectGATTIfConnected();
 }
@@ -62,7 +60,7 @@ const WTF::AtomicString& BluetoothDevice::interfaceName() const
 
 ExecutionContext* BluetoothDevice::getExecutionContext() const
 {
-    return ActiveDOMObject::getExecutionContext();
+    return ContextLifecycleObserver::getExecutionContext();
 }
 
 void BluetoothDevice::dispatchGattServerDisconnected()
@@ -77,7 +75,7 @@ void BluetoothDevice::dispatchGattServerDisconnected()
 DEFINE_TRACE(BluetoothDevice)
 {
     EventTargetWithInlineData::trace(visitor);
-    ActiveDOMObject::trace(visitor);
+    ContextLifecycleObserver::trace(visitor);
     visitor->trace(m_gatt);
 }
 

third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.h

@@ -6,7 +6,7 @@
 #define BluetoothDevice_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
-#include "core/dom/ActiveDOMObject.h"
+#include "core/dom/ContextLifecycleObserver.h"
 #include "modules/EventTargetModules.h"
 #include "modules/bluetooth/BluetoothRemoteGATTServer.h"
 #include "platform/heap/Heap.h"
@@ -29,7 +29,7 @@ class ScriptPromiseResolver;
 // CallbackPromiseAdapter class comments.
 class BluetoothDevice final
     : public EventTargetWithInlineData
-    , public ActiveDOMObject
+    , public ContextLifecycleObserver
     , public WebBluetoothDevice {
     USING_PRE_FINALIZER(BluetoothDevice, dispose);
     DEFINE_WRAPPERTYPEINFO();
@@ -54,8 +54,8 @@ public:
     // Called before the object gets garbage collected.
     void dispose();
 
-    // ActiveDOMObject interface.
-    void stop() override;
+    // ContextLifecycleObserver interface.
+    void contextDestroyed() override;
 
     // If gatt is connected then disconnects and sets gatt.connected to false.
     // Returns true if gatt was disconnected.