Oilpan: Notify supplements of Page and LocalFrame destruction.

Source/modules/screen_orientation/ScreenOrientationController.cpp

Index: Source/modules/screen_orientation/ScreenOrientationController.cpp
diff --git a/Source/modules/screen_orientation/ScreenOrientationController.cpp b/Source/modules/screen_orientation/ScreenOrientationController.cpp
index aecdcc881df2c957d559d495c1248cc43d990b1d..a553065ef8cedba490184814bd55abcc45b60667 100644
--- a/Source/modules/screen_orientation/ScreenOrientationController.cpp
+++ b/Source/modules/screen_orientation/ScreenOrientationController.cpp
@@ -22,6 +22,12 @@ ScreenOrientationController::~ScreenOrientationController()
 {
 }
 
+void ScreenOrientationController::persistentHostHasBeenDestroyed()
+{
+    // Unregister lifecycle observation once page is being torn down.
+    observeContext(0);
+}
+
 void ScreenOrientationController::provideTo(LocalFrame& frame, blink::WebScreenOrientationClient* client)
 {
     ScreenOrientationController* controller = new ScreenOrientationController(frame, client);