Move PlatformEventDispatcher implementations to the Oilpan heap.

Source/modules/gamepad/GamepadDispatcher.h

Index: Source/modules/gamepad/GamepadDispatcher.h
diff --git a/Source/modules/gamepad/GamepadDispatcher.h b/Source/modules/gamepad/GamepadDispatcher.h
index 4bd3ea3e0248f9074af99d3f3222605c622c0dd1..cc154cb4df0e25476d8c4f5809abcb09a6891c9d 100644
--- a/Source/modules/gamepad/GamepadDispatcher.h
+++ b/Source/modules/gamepad/GamepadDispatcher.h
@@ -15,9 +15,11 @@ namespace blink {
 class NavigatorGamepad;
 class WebGamepads;
 
-class GamepadDispatcher : public PlatformEventDispatcher, public WebGamepadListener {
+class GamepadDispatcher final : public GarbageCollectedFinalized<GamepadDispatcher>, public PlatformEventDispatcher, public WebGamepadListener {
+    USING_GARBAGE_COLLECTED_MIXIN(GamepadDispatcher);
 public:
     static GamepadDispatcher& instance();
+    virtual ~GamepadDispatcher();
 
     void sampleGamepads(WebGamepads&);
 
@@ -28,17 +30,18 @@ public:
 
     const ConnectionChange& latestConnectionChange() const { return m_latestChange; }
 
+    virtual void trace(Visitor*) override;
+
 private:
     GamepadDispatcher();
-    virtual ~GamepadDispatcher();
 
     // WebGamepadListener
-    virtual void didConnectGamepad(unsigned index, const WebGamepad&) OVERRIDE;
-    virtual void didDisconnectGamepad(unsigned index, const WebGamepad&) OVERRIDE;
+    virtual void didConnectGamepad(unsigned index, const WebGamepad&) override;
+    virtual void didDisconnectGamepad(unsigned index, const WebGamepad&) override;
 
     // PlatformEventDispatcher
-    virtual void startListening() OVERRIDE;
-    virtual void stopListening() OVERRIDE;
+    virtual void startListening() override;
+    virtual void stopListening() override;
 
     void dispatchDidConnectOrDisconnectGamepad(unsigned index, const WebGamepad&, bool connected);