[WebSocket] Remove Quota System from data transfer

This commit removes the quota system from renderer to network service
data transfer, and moves completely to mojo data pipe.

This is a follow-up CL from the following CLs:
https://chromium-review.googlesource.com/c/chromium/src/+/2071189
https://chromium-review.googlesource.com/c/chromium/src/+/2206556

Design Doc:
https://docs.google.com/document/d/1YWj1z9r8wxemGdod6S2tkchudhp6PvNaH3qSO0oucfY/

This is a rebase of
https://chromium-review.googlesource.com/c/chromium/src/+/2120193,
originally by Keita Suzuki.

Bug: 1056030
Change-Id: Ibc84448e56cad0cc2d8d4ed4a2ef4411b28be104
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2210333
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Eric Roman <eroman@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Eric Roman <eroman@chromium.org>
Auto-Submit: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#771824}

chrome/browser/net/websocket_browsertest.cc

@@ -409,8 +409,6 @@ class ExpectInvalidUtf8Client : public network::mojom::WebSocketClient {
     NOTREACHED();
   }
 
-  void AddSendFlowControlQuota(int64_t quota) override {}
-
   void OnDropChannel(bool was_clean,
                      uint16_t code,
                      const std::string& reason) override {

net/websockets/websocket_channel.cc

@@ -44,7 +44,6 @@ namespace {
 
 using base::StreamingUtf8Validator;
 
-const int kDefaultSendQuotaHighWaterMark = 1 << 17;
 const size_t kWebSocketCloseCodeLength = 2;
 // Timeout for waiting for the server to acknowledge a closing handshake.
 const int kClosingHandshakeTimeoutSeconds = 60;
@@ -285,8 +284,6 @@ WebSocketChannel::WebSocketChannel(
     URLRequestContext* url_request_context)
     : event_interface_(std::move(event_interface)),
       url_request_context_(url_request_context),
-      send_quota_high_water_mark_(kDefaultSendQuotaHighWaterMark),
-      current_send_quota_(0),
       closing_handshake_timeout_(
           base::TimeDelta::FromSeconds(kClosingHandshakeTimeoutSeconds)),
       underlying_connection_close_timeout_(base::TimeDelta::FromSeconds(
@@ -373,10 +370,7 @@ WebSocketChannel::ChannelState WebSocketChannel::SendFrame(
     sending_text_message_ = !fin;
     DCHECK(!fin || state == StreamingUtf8Validator::VALID_ENDPOINT);
   }
-  // TODO(ricea): If current_send_quota_ has dropped below
-  // send_quota_low_water_mark_, it might be good to increase the "low
-  // water mark" and "high water mark", but only if the link to the WebSocket
-  // server is not saturated.
+
   return SendFrameInternal(fin, op_code, std::move(buffer), buffer_size);
   // |this| may have been deleted.
 }
@@ -510,12 +504,8 @@ void WebSocketChannel::OnConnectSuccess(
   // |stream_request_| is not used once the connection has succeeded.
   stream_request_.reset();
 
-  // TODO(ricea): Get flow control information from the WebSocketStream once we
-  // have a multiplexing WebSocketStream.
-  current_send_quota_ = send_quota_high_water_mark_;
   event_interface_->OnAddChannelResponse(
-      std::move(response), stream_->GetSubProtocol(), stream_->GetExtensions(),
-      send_quota_high_water_mark_);
+      std::move(response), stream_->GetSubProtocol(), stream_->GetExtensions());
   // |this| may have been deleted after OnAddChannelResponse.
 }
 
@@ -938,8 +928,6 @@ ChannelState WebSocketChannel::SendFrameInternal(
   if (data_being_sent_) {
     // Either the link to the WebSocket server is saturated, or several messages
     // are being sent in a batch.
-    // TODO(ricea): Keep some statistics to work out the situation and adjust
-    // quota appropriately.
     if (!data_to_send_next_)
       data_to_send_next_ = std::make_unique<SendBuffer>();
     data_to_send_next_->AddFrame(std::move(frame), std::move(buffer));
@@ -993,6 +981,7 @@ ChannelState WebSocketChannel::SendClose(uint16_t code,
     std::copy(
         reason.begin(), reason.end(), body->data() + kWebSocketCloseCodeLength);
   }
+
   return SendFrameInternal(true, WebSocketFrameHeader::kOpCodeClose,
                            std::move(body), size);
 }

net/websockets/websocket_channel.h

@@ -118,12 +118,6 @@ class NET_EXPORT WebSocketChannel {
   ChannelState StartClosingHandshake(uint16_t code, const std::string& reason)
       WARN_UNUSED_RESULT;
 
-  // Returns the current send quota. This value is unsafe to use outside of the
-  // browser IO thread because it changes asynchronously.  The value is only
-  // valid for the execution of the current Task or until SendFrame() is called,
-  // whichever happens sooner.
-  int current_send_quota() const { return current_send_quota_; }
-
   // Starts the connection process, using a specified creator callback rather
   // than the default. This is exposed for testing.
   void SendAddChannelRequestForTesting(
@@ -359,13 +353,6 @@ class NET_EXPORT WebSocketChannel {
   // during the connection process.
   std::unique_ptr<WebSocketStreamRequest> stream_request_;
 
-  // The level the quota is refreshed to when it reaches the low_water_mark
-  // (quota units).
-  int send_quota_high_water_mark_;
-  // The current amount of quota that the renderer has available for sending
-  // on this logical channel (quota units).
-  int current_send_quota_;
-
   // Timer for the closing handshake.
   base::OneShotTimer close_timer_;