Allow the SwapQueue to utilize user-define swap capability

The SwapQueue class provides efficient and thread-safe queueing of objects that
have swap capabilities. However, the current implementation does not utilize the
user-defined swap capabilites. This CL addresses that.

Bug: b/168693942
Change-Id: Id5c97c8c9cc04579b3c26c7f1dc5f8b3362126c4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/184361
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32118}
diff --git a/rtc_base/swap_queue.h b/rtc_base/swap_queue.h
index eb0b1ff..9eac49a 100644
--- a/rtc_base/swap_queue.h
+++ b/rtc_base/swap_queue.h
@@ -141,7 +141,8 @@
       return false;
     }
 
-    std::swap(*input, queue_[next_write_index_]);
+    using std::swap;
+    swap(*input, queue_[next_write_index_]);
 
     // Increment the value of num_elements_ to account for the inserted element.
     // Release memory ordering prevents the reads and writes to
@@ -181,7 +182,8 @@
       return false;
     }
 
-    std::swap(*output, queue_[next_read_index_]);
+    using std::swap;
+    swap(*output, queue_[next_read_index_]);
 
     // Decrement the value of num_elements_ to account for the removed element.
     // Release memory ordering prevents the reads and writes to