fix instances of bugprone-argument-comment

This new clang-tidy check complains when param names /*in_comments=*/
don't match up with the actual parameter name they're being passed to.
Sometimes this is benign, other times, actual bugs are found.

Bug: 1136209
Change-Id: I9802951e5f8d4d77d0c0ae2a3f69134f93b548df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2459427Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: George Burgess <gbiv@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815685}

content/browser/keyboard_lock_browsertest.cc

@@ -649,7 +649,7 @@ IN_PROC_BROWSER_TEST_F(KeyboardLockBrowserTest,
 
   // The first child has the same origin as the top-level domain.
   RenderFrameHost* child_frame = ChildFrameAt(web_contents()->GetMainFrame(),
-                                              /*child_index=*/0);
+                                              /*index=*/0);
   ASSERT_TRUE(child_frame);
 
   bool api_exists = false;
@@ -671,7 +671,7 @@ IN_PROC_BROWSER_TEST_F(KeyboardLockBrowserTest,
 
   // The second child has a different origin as the top-level domain.
   RenderFrameHost* child_frame = ChildFrameAt(web_contents()->GetMainFrame(),
-                                              /*child_index=*/1);
+                                              /*index=*/1);
   ASSERT_TRUE(child_frame);
 
   bool api_exists = false;