Make XRPlaneDetectionState constructor explicit, remove default argument

Change-Id: I6e1109cf6ab7b8e3a40910fec3f2e9a54cb4d578
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1994267
Commit-Queue: Will Cassella <cassew@google.com>
Reviewed-by: Piotr Bialecki <bialpio@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732308}

third_party/blink/renderer/modules/xr/xr_plane_detection_state.h

@@ -17,8 +17,8 @@ class XRPlaneDetectionState : public ScriptWrappable {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
-  XRPlaneDetectionState(
-      XRPlaneDetectionStateInit* plane_detection_state_init = nullptr);
+  explicit XRPlaneDetectionState(
+      XRPlaneDetectionStateInit* plane_detection_state_init);
 
   bool enabled() const { return enabled_; }