[Android, RemotePlayback] Make RemotePlayback classes ActiveScriptWrappable's

Keeps the V8 wrappers alive as long as there're event listeners or pending
promises and such.

BUG=616761
TEST=manual, see repro steps in the bug

Review-Url: https://codereview.chromium.org/2038573002
Cr-Commit-Position: refs/heads/master@{#398014}

third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.cpp

@@ -47,7 +47,7 @@ RemotePlayback* RemotePlayback::create(HTMLMediaElement& element)
 }
 
 RemotePlayback::RemotePlayback(HTMLMediaElement& element)
-    : DOMWindowProperty(element.document().frame())
+    : ActiveScriptWrappable(this)
     , m_state(element.isPlayingRemotely() ? WebRemotePlaybackState::Connected : WebRemotePlaybackState::Disconnected)
     , m_availability(element.hasRemoteRoutes())
     , m_mediaElement(&element)
@@ -61,9 +61,7 @@ const AtomicString& RemotePlayback::interfaceName() const
 
 ExecutionContext* RemotePlayback::getExecutionContext() const
 {
-    if (!m_frame)
-        return 0;
-    return m_frame->document();
+    return &m_mediaElement->document();
 }
 
 ScriptPromise RemotePlayback::getAvailability(ScriptState* scriptState)
@@ -110,6 +108,13 @@ String RemotePlayback::state() const
     return remotePlaybackStateToString(m_state);
 }
 
+bool RemotePlayback::hasPendingActivity() const
+{
+    return hasEventListeners()
+        || !m_availabilityObjects.isEmpty()
+        || !m_connectPromiseResolvers.isEmpty();
+}
+
 void RemotePlayback::stateChanged(WebRemotePlaybackState state)
 {
     // We may get a "disconnected" state change while in the "disconnected"
@@ -153,10 +158,9 @@ void RemotePlayback::connectCancelled()
 DEFINE_TRACE(RemotePlayback)
 {
     visitor->trace(m_availabilityObjects);
-    visitor->trace(m_mediaElement);
     visitor->trace(m_connectPromiseResolvers);
+    visitor->trace(m_mediaElement);
     EventTargetWithInlineData::trace(visitor);
-    DOMWindowProperty::trace(visitor);
 }
 
 } // namespace blink

third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.h

@@ -5,9 +5,9 @@
 #ifndef RemotePlayback_h
 #define RemotePlayback_h
 
+#include "bindings/core/v8/ActiveScriptWrappable.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "core/events/EventTarget.h"
-#include "core/frame/DOMWindowProperty.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/modules/remoteplayback/WebRemotePlaybackClient.h"
 #include "public/platform/modules/remoteplayback/WebRemotePlaybackState.h"
@@ -24,7 +24,7 @@ class ScriptPromiseResolver;
 
 class RemotePlayback final
     : public EventTargetWithInlineData
-    , public DOMWindowProperty
+    , public ActiveScriptWrappable
     , private WebRemotePlaybackClient {
     DEFINE_WRAPPERTYPEINFO();
     USING_GARBAGE_COLLECTED_MIXIN(RemotePlayback);
@@ -40,6 +40,9 @@ public:
 
     String state() const;
 
+    // ActiveScriptWrappable implementation.
+    bool hasPendingActivity() const final;
+
     DEFINE_ATTRIBUTE_EVENT_LISTENER(statechange);
 
     DECLARE_VIRTUAL_TRACE();

third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.idl

@@ -10,6 +10,8 @@ enum RemotePlaybackState {
 };
 
 [
+    ActiveScriptWrappable,
+    DependentLifetime,
     RuntimeEnabled=RemotePlayback
 ] interface RemotePlayback : EventTarget {
     readonly attribute RemotePlaybackState state;

third_party/WebKit/Source/modules/remoteplayback/RemotePlaybackAvailability.cpp

@@ -18,7 +18,8 @@ RemotePlaybackAvailability* RemotePlaybackAvailability::take(ScriptPromiseResolv
 }
 
 RemotePlaybackAvailability::RemotePlaybackAvailability(ExecutionContext* executionContext, bool value)
-    : ContextLifecycleObserver(executionContext)
+    : ActiveScriptWrappable(this)
+    , ContextLifecycleObserver(executionContext)
     , m_value(value)
 {
     ASSERT(executionContext->isDocument());
@@ -50,6 +51,11 @@ bool RemotePlaybackAvailability::value() const
     return m_value;
 }
 
+bool RemotePlaybackAvailability::hasPendingActivity() const
+{
+    return hasEventListeners();
+}
+
 DEFINE_TRACE(RemotePlaybackAvailability)
 {
     EventTargetWithInlineData::trace(visitor);

third_party/WebKit/Source/modules/remoteplayback/RemotePlaybackAvailability.h

@@ -5,6 +5,7 @@
 #ifndef RemotePlaybackAvailability_h
 #define RemotePlaybackAvailability_h
 
+#include "bindings/core/v8/ActiveScriptWrappable.h"
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/events/EventTarget.h"
 
@@ -16,7 +17,10 @@ class ScriptPromiseResolver;
 // Expose whether there is a remote playback device available for a media
 // element. The object will be initialized with a default value passed via
 // ::take() and will then listen to availability changes.
-class RemotePlaybackAvailability final : public EventTargetWithInlineData, public ContextLifecycleObserver {
+class RemotePlaybackAvailability final
+    : public EventTargetWithInlineData
+    , public ActiveScriptWrappable
+    , public ContextLifecycleObserver {
     DEFINE_WRAPPERTYPEINFO();
     USING_GARBAGE_COLLECTED_MIXIN(RemotePlaybackAvailability);
 public:
@@ -31,6 +35,9 @@ public:
 
     bool value() const;
 
+    // ActiveScriptWrappable implementation.
+    bool hasPendingActivity() const final;
+
     DEFINE_ATTRIBUTE_EVENT_LISTENER(change);
 
     DECLARE_VIRTUAL_TRACE();

third_party/WebKit/Source/modules/remoteplayback/RemotePlaybackAvailability.idl

@@ -5,6 +5,8 @@
 // https://w3c.github.io/remote-playback/#idl-def-remoteplaybackavailability
 
 [
+    ActiveScriptWrappable,
+    DependentLifetime,
     RuntimeEnabled=RemotePlayback,
 ] interface RemotePlaybackAvailability : EventTarget {
     readonly attribute boolean value;