Tidy: Mark LaunchParams constructor explicit

Bug: N/A
Change-Id: I533db48d7d38b194549a9b283c5a4ce9da51ae0e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2601636
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Auto-Submit: Austin Sullivan <asully@chromium.org>
Cr-Commit-Position: refs/heads/master@{#839793}

third_party/blink/renderer/modules/launch/launch_params.h

@@ -18,7 +18,7 @@ class LaunchParams final : public ScriptWrappable {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
-  LaunchParams(HeapVector<Member<NativeFileSystemHandle>> files);
+  explicit LaunchParams(HeapVector<Member<NativeFileSystemHandle>> files);
   ~LaunchParams() override;
 
   // LaunchParams IDL interface.