Fix wrong request id on OnGetNearestFindResultReply binding

The wrong request id is used while binding OnGetNearestFindResultReply.
The original IPC version used activate_.current_request_id but we used
current_session_id_ in the mojoification on crrev.com/c/1051143, making
replies received in OnGetNearestFindResultReply to be dropped because
the request id don't match.

This CL makes the mojo call to use activate_.current_request_id.

Bug: 843448
Change-Id: I049d4f560ed82d36f8d3ffb876217ba94a46fe1c
Reviewed-on: https://chromium-review.googlesource.com/1063045Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Commit-Queue: Rakina Zata Amni <rakina@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559403}

content/browser/find_request_manager.cc

@@ -462,7 +462,8 @@ void FindRequestManager::ActivateNearestFindResult(float x, float y) {
       rfh->GetFindInPage()->GetNearestFindResult(
           gfx::PointF(activate_.x, activate_.y),
           base::BindOnce(&FindRequestManager::OnGetNearestFindResultReply,
-                         base::Unretained(this), rfh, current_session_id_));
+                         base::Unretained(this), rfh,
+                         activate_.current_request_id));
     }
   }
 }