Per-renderer WebSocket throttling

content/browser/renderer_host/websocket_host.cc

Index: content/browser/renderer_host/websocket_host.cc
diff --git a/content/browser/renderer_host/websocket_host.cc b/content/browser/renderer_host/websocket_host.cc
index 84caa8cfb1157d3f0ee3c015e851be977879b449..a8ed959709fcf056c5dfe9365b6091570efef50e 100644
--- a/content/browser/renderer_host/websocket_host.cc
+++ b/content/browser/renderer_host/websocket_host.cc
@@ -314,10 +314,15 @@ void WebSocketEventHandler::SSLErrorHandlerDelegate::ContinueSSLRequest() {
 
 WebSocketHost::WebSocketHost(int routing_id,
                              WebSocketDispatcherHost* dispatcher,
-                             net::URLRequestContext* url_request_context)
+                             net::URLRequestContext* url_request_context,
+                             int delay_in_ms)
     : dispatcher_(dispatcher),
       url_request_context_(url_request_context),
-      routing_id_(routing_id) {
+      routing_id_(routing_id),
+      delay_in_ms_(delay_in_ms),
+      pending_flow_control_quota_(-1),
+      handshake_succeeded_(false),
+      weak_ptr_factory_(this) {
   DVLOG(1) << "WebSocketHost: created routing_id=" << routing_id;
 }
 
@@ -351,11 +356,43 @@ void WebSocketHost::OnAddChannelRequest(
            << origin.string() << "\"";
 
   DCHECK(!channel_);
+  if (delay_in_ms_ > 0) {
+    base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&WebSocketHost::AddChannel,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   socket_url,
+                   requested_protocols,
+                   origin,
+                   render_frame_id),
+        base::TimeDelta::FromMilliseconds(delay_in_ms_));
+  } else {
+    AddChannel(socket_url, requested_protocols, origin, render_frame_id);
+  }
+}
+
+void WebSocketHost::AddChannel(
+    const GURL& socket_url,
+    const std::vector<std::string>& requested_protocols,
+    const url::Origin& origin,
+    int render_frame_id) {
+  DVLOG(3) << "WebSocketHost::AddChannel"
+           << " routing_id=" << routing_id_ << " socket_url=\"" << socket_url
+           << "\" requested_protocols=\""
+           << JoinString(requested_protocols, ", ") << "\" origin=\""
+           << origin.string() << "\"";
+
+  DCHECK(!channel_);
+
   scoped_ptr<net::WebSocketEventInterface> event_interface(
       new WebSocketEventHandler(dispatcher_, routing_id_, render_frame_id));
   channel_.reset(
       new net::WebSocketChannel(event_interface.Pass(), url_request_context_));
   channel_->SendAddChannelRequest(socket_url, requested_protocols, origin);
+
+  if (pending_flow_control_quota_ >= 0) {
+    channel_->SendFlowControl(pending_flow_control_quota_);

[Adam Rice, 2015/03/03 15:10:03]

I suggest setting pending_flow_control_quota_ to 0, just to be safe.

[hiroshige, 2015/03/04 06:02:38]

Done.

+  }
 }
 
 void WebSocketHost::OnSendFrame(bool fin,
@@ -373,7 +410,14 @@ void WebSocketHost::OnFlowControl(int64 quota) {
   DVLOG(3) << "WebSocketHost::OnFlowControl"
            << " routing_id=" << routing_id_ << " quota=" << quota;
 
-  DCHECK(channel_);
+  if (!channel_) {
+    // WebSocketChannel is not yet created due to the delay introduced by
+    // Per-renderer WebSocket throttling.
+    // SendFlowControl() is called after WebSocketChannel is created.
+    pending_flow_control_quota_ = quota;

[Adam Rice, 2015/03/03 15:10:02]

This should be += because flow control quota is always added to any remaining
quota. It doesn't make any difference at the moment because the renderer only
sends one FlowControl message before data is received, but the implementation
could change in future.

[hiroshige, 2015/03/04 06:02:38]

Done.

+    return;
+  }
+
   channel_->SendFlowControl(quota);
 }
 
@@ -384,7 +428,15 @@ void WebSocketHost::OnDropChannel(bool was_clean,
            << " routing_id=" << routing_id_ << " was_clean=" << was_clean
            << " code=" << code << " reason=\"" << reason << "\"";
 
-  DCHECK(channel_);
+  if (!channel_) {
+    // WebSocketChannel is not yet created due to the delay introduced by
+    // Per-renderer WebSocket throttling.
+    WebSocketDispatcherHost::WebSocketHostState result =
+        dispatcher_->DoDropChannel(routing_id_, was_clean, code, reason);

[Adam Rice, 2015/03/03 15:10:03]

We should not use the values from the renderer in DoDropChannel. It should be
was_clean = false, code = kWebSocketErrorAbnormalClosure and reason = "", the
same as at websocket_channel.cc:484 (
https://code.google.com/p/chromium/codesearch#chromium/src/net/websockets/web...
)

[hiroshige, 2015/03/04 06:02:38]

Done.

+    DCHECK_EQ(WebSocketDispatcherHost::WEBSOCKET_HOST_DELETED, result);
+    return;
+  }
+
   // TODO(yhirano): Handle |was_clean| appropriately.
   channel_->StartClosingHandshake(code, reason);
 }