Fix the buffer size switching in WebSocket

buffer_size_ should keep the CURRENT size of read_buffer_. Before this
change, buffer_size_ is not updated and keeps the initial size till the
end. It causes vain buffer reallocations when processing high throughput
connections.
The change in this CL makes buffer_size_ updated every time the size of
read_buffer_ is switched.

Change-Id: I924663165cb7996833a29313ce801b68e2c11829
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3423345
Reviewed-by: Adam Rice <[email protected]>
Reviewed-by: Yutaka Hirano <[email protected]>
Commit-Queue: Nanami Mikiya <[email protected]>
Cr-Commit-Position: refs/heads/main@{#965056}
diff --git a/net/websockets/websocket_basic_stream.cc b/net/websockets/websocket_basic_stream.cc
index c4d091c..c0e546b 100644
--- a/net/websockets/websocket_basic_stream.cc
+++ b/net/websockets/websocket_basic_stream.cc
@@ -269,6 +269,7 @@
           buffer_size_manager_.buffer_size() == BufferSize::kSmall
               ? kSmallReadBufferSize
               : kLargeReadBufferSize);
+      buffer_size_ = buffer_size_manager_.buffer_size();
     }
     buffer_size_manager_.OnRead(base::TimeTicks::Now());