From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samuel Attard <samuel.r.attard@gmail.com>
Date: Tue, 5 Sep 2023 13:22:31 -0700
Subject: Revert "Remove the AllowAggressiveThrottlingWithWebSocket feature."

This reverts commit 615c1810a187840ffeb04096087efff86edb37de.

diff --git a/third_party/blink/renderer/modules/websockets/websocket_channel_impl.cc b/third_party/blink/renderer/modules/websockets/websocket_channel_impl.cc
index c9614216a384f5d99f54c277a139e6332463bac5..fc3d22604f209d7ec530f078ece503070116e1ea 100644
--- a/third_party/blink/renderer/modules/websockets/websocket_channel_impl.cc
+++ b/third_party/blink/renderer/modules/websockets/websocket_channel_impl.cc
@@ -96,6 +96,17 @@ enum WebSocketOpCode {
   kOpCodeBinary = 0x2,
 };
 
+// When enabled, a page can be aggressively throttled even if it uses a
+// WebSocket. Aggressive throttling does not affect the execution of WebSocket
+// event handlers, so there is little reason to disable it on pages using a
+// WebSocket.
+//
+// TODO(crbug.com/1121725): Cleanup this feature in June 2021, when it becomes
+// enabled by default on Stable.
+BASE_FEATURE(kAllowAggressiveThrottlingWithWebSocket,
+             "AllowAggressiveThrottlingWithWebSocket",
+             base::FEATURE_ENABLED_BY_DEFAULT);
+
 }  // namespace
 
 void WebSocketChannelImpl::MessageDataDeleter::operator()(char* p) const {
@@ -286,7 +297,10 @@ bool WebSocketChannelImpl::Connect(const KURL& url, const String& protocol) {
     // even if the `WebSocketChannel` is closed.
     feature_handle_for_scheduler_ = scheduler->RegisterFeature(
         SchedulingPolicy::Feature::kWebSocket,
-        SchedulingPolicy{SchedulingPolicy::DisableBackForwardCache()});
+        base::FeatureList::IsEnabled(kAllowAggressiveThrottlingWithWebSocket)
+            ? SchedulingPolicy{SchedulingPolicy::DisableBackForwardCache()}
+            : SchedulingPolicy{SchedulingPolicy::DisableAggressiveThrottling(),
+                               SchedulingPolicy::DisableBackForwardCache()});
     scheduler->RegisterStickyFeature(
         SchedulingPolicy::Feature::kWebSocketSticky,
         SchedulingPolicy{SchedulingPolicy::DisableBackForwardCache()});
