WebXR - hit test & DOM overlay - fix hit test results

Invisible input sources should not cause their hit test results to be
surfaced to the application.

Change-Id: Id6aff539db20981d78d57098b2f0335ca352319b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2098852
Commit-Queue: Klaus Weidner <klausw@chromium.org>
Auto-Submit: Piotr Bialecki <bialpio@chromium.org>
Reviewed-by: Klaus Weidner <klausw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#749357}

third_party/blink/renderer/modules/xr/xr_hit_test_source.cc

@@ -53,6 +53,7 @@ void XRHitTestSource::Update(
     last_frame_results_.push_back(*result);
   }
 }
+
 void XRHitTestSource::Trace(Visitor* visitor) {
   visitor->Trace(xr_session_);
   ScriptWrappable::Trace(visitor);

third_party/blink/renderer/modules/xr/xr_transient_input_hit_test_source.cc

@@ -60,9 +60,12 @@ void XRTransientInputHitTestSource::Update(
     if (!input_source)
       continue;
 
-    current_frame_results_.push_back(
-        MakeGarbageCollected<XRTransientInputHitTestResult>(
-            input_source, source_id_and_results.value));
+    // If the input source is not visible, ignore it.
+    if (input_source->IsVisible()) {
+      current_frame_results_.push_back(
+          MakeGarbageCollected<XRTransientInputHitTestResult>(
+              input_source, source_id_and_results.value));
+    }
   }
 }