Move PlatformEventDispatcher implementations to the Oilpan heap.

Source/modules/device_orientation/DeviceOrientationDispatcher.cpp

Index: Source/modules/device_orientation/DeviceOrientationDispatcher.cpp
diff --git a/Source/modules/device_orientation/DeviceOrientationDispatcher.cpp b/Source/modules/device_orientation/DeviceOrientationDispatcher.cpp
index 9b24851d369621eb80763bedb61755bc1a58a621..07ddc56e075ee730358b9852ac1b0a95522c95da 100644
--- a/Source/modules/device_orientation/DeviceOrientationDispatcher.cpp
+++ b/Source/modules/device_orientation/DeviceOrientationDispatcher.cpp
@@ -39,8 +39,8 @@ namespace blink {
 
 DeviceOrientationDispatcher& DeviceOrientationDispatcher::instance()
 {
-    DEFINE_STATIC_LOCAL(DeviceOrientationDispatcher, deviceOrientationDispatcher, ());
-    return deviceOrientationDispatcher;
+    DEFINE_STATIC_LOCAL(Persistent<DeviceOrientationDispatcher>, deviceOrientationDispatcher, (new DeviceOrientationDispatcher()));
+    return *deviceOrientationDispatcher;
 }
 
 DeviceOrientationDispatcher::DeviceOrientationDispatcher()
@@ -51,6 +51,12 @@ DeviceOrientationDispatcher::~DeviceOrientationDispatcher()
 {
 }
 
+void DeviceOrientationDispatcher::trace(Visitor* visitor)
+{
+    visitor->trace(m_lastDeviceOrientationData);
+    PlatformEventDispatcher::trace(visitor);
+}
+
 void DeviceOrientationDispatcher::startListening()
 {
     Platform::current()->startListening(WebPlatformEventDeviceOrientation, this);