Remove Webview Overlays on destroy

When WebViewFunctor is destroyed, overlays needs to be removed.
Bug: 194393522
Test: toggle fullscreen during video playing, and run "adb shell dumpsys
SurfaceFlinger | grep Webview", it should only show onlyi one surface
control

Change-Id: I40d0e503c4f5b25c59886820485e7734716ac859
(cherry picked from commit 9c5158f7a2)

libs/hwui/WebViewFunctorManager.cpp

@@ -100,6 +100,9 @@ WebViewFunctor::~WebViewFunctor() {
     destroyContext();
 
     ATRACE_NAME("WebViewFunctor::onDestroy");
+    if (mSurfaceControl) {
+        removeOverlays();
+    }
     mCallbacks.onDestroyed(mFunctor, mData);
 }