Fix drag and drop (2/3)

Handle InputWindowCommands in SurfaceFlinger. Send transferTouchFocus from
SurfaceFlinger to InputFlinger.

Test: InputSurfacesTest.transfer_touch_focus
Bug: 120463595
Change-Id: I6592cc9ee4a77700ea191fd1ca337b91895b61fe
diff --git a/services/inputflinger/host/InputFlinger.h b/services/inputflinger/host/InputFlinger.h
index 82ff089..9d0be95 100644
--- a/services/inputflinger/host/InputFlinger.h
+++ b/services/inputflinger/host/InputFlinger.h
@@ -40,6 +40,7 @@
 
     virtual status_t dump(int fd, const Vector<String16>& args);
     void setInputWindows(const Vector<InputWindowInfo>&) {}
+    void transferTouchFocus(const sp<IBinder>&, const sp<IBinder>&) {}
     void registerInputChannel(const sp<InputChannel>&) {}
     void unregisterInputChannel(const sp<InputChannel>&) {}