Update test_driver.click() documentation to specify "mouse" click.

#48158

Change-Id: Ic3c18dd7ae76077fa2303018918777dc04d82022
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5861351
Commit-Queue: Robert Flack <flackr@chromium.org>
Auto-Submit: Mustaq Ahmed <mustaq@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1358149}

resources/testdriver.js

@@ -176,11 +176,10 @@
         },
 
         /**
-         * Triggers a user-initiated click
+         * Triggers a user-initiated mouse click.
          *
-         * If ``element`` isn't inside the
-         * viewport, it will be scrolled into view before the click
-         * occurs.
+         * If ``element`` isn't inside the viewport, it will be
+         * scrolled into view before the click occurs.
          *
          * If ``element`` is from a different browsing context, the
          * command will be run in that context.