Temporarily remove ConnectionListener from the public API (#8831)

I'd like to update the API to improve observability into things
like ConnecitonPool, RoutePlanner, ConnectPlan, and ReusePlan.
And also into HTTP/2 internals like flow-control.

As-is this is more coupled to Call lifecycles and is somewhat
duplicative with ConnectionPool.

We'll do that work and make it a new public API, but we won't
have it in the public API at all for the 5.0 release.

Co-authored-by: Jesse Wilson <jwilson@squareup.com>

okhttp-testing-support/src/main/kotlin/okhttp3/ConnectionEvent.kt

@@ -13,6 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+@file:Suppress(
+  "CANNOT_OVERRIDE_INVISIBLE_MEMBER",
+  "INVISIBLE_MEMBER",
+  "INVISIBLE_REFERENCE",
+)
 
 package okhttp3
 

okhttp-testing-support/src/main/kotlin/okhttp3/OkHttpClientTestRule.kt

@@ -60,7 +60,7 @@ class OkHttpClientTestRule :
   private lateinit var testName: String
   private var defaultUncaughtExceptionHandler: Thread.UncaughtExceptionHandler? = null
   private var taskQueuesWereIdle: Boolean = false
-  val connectionListener = RecordingConnectionListener()
+  private val connectionListener = RecordingConnectionListener()
 
   var logger: Logger? = null
 

okhttp-testing-support/src/main/kotlin/okhttp3/RecordingConnectionListener.kt

@@ -13,6 +13,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+@file:Suppress(
+  "CANNOT_OVERRIDE_INVISIBLE_MEMBER",
+  "INVISIBLE_MEMBER",
+  "INVISIBLE_REFERENCE",
+)
+
 package okhttp3
 
 import assertk.assertThat
@@ -24,11 +30,12 @@ import java.util.Deque
 import java.util.concurrent.ConcurrentLinkedDeque
 import java.util.concurrent.TimeUnit
 import okhttp3.ConnectionEvent.NoNewExchanges
+import okhttp3.internal.connection.ConnectionListener
 import okhttp3.internal.connection.RealConnection
 import okio.IOException
 import org.junit.jupiter.api.Assertions
 
-open class RecordingConnectionListener(
+internal open class RecordingConnectionListener(
   /**
    * An override to ignore the normal order that is enforced.
    * EventListeners added by Interceptors will not see all events.

okhttp-testing-support/src/main/kotlin/okhttp3/TestValueFactory.kt

@@ -36,6 +36,7 @@ import okhttp3.internal.concurrent.TaskFaker
 import okhttp3.internal.concurrent.TaskRunner
 import okhttp3.internal.concurrent.withLock
 import okhttp3.internal.connection.CallConnectionUser
+import okhttp3.internal.connection.ConnectionListener
 import okhttp3.internal.connection.FastFallbackExchangeFinder
 import okhttp3.internal.connection.RealCall
 import okhttp3.internal.connection.RealConnection

okhttp-testing-support/src/main/kotlin/okhttp3/internal/http2/Http2FlowControlConnectionListener.kt

@@ -1,40 +0,0 @@
-/*
- * Copyright (C) 2023 Block, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package okhttp3.internal.http2
-
-import okhttp3.ConnectionListener
-import okhttp3.internal.http2.flowcontrol.WindowCounter
-
-/**
- * ConnectionListener that outputs CSV for flow control of client receiving streams.
- */
-class Http2FlowControlConnectionListener :
-  ConnectionListener(),
-  FlowControlListener {
-  val start = System.currentTimeMillis()
-
-  override fun receivingStreamWindowChanged(
-    streamId: Int,
-    windowCounter: WindowCounter,
-    bufferSize: Long,
-  ) {
-    println("${System.currentTimeMillis() - start},$streamId,${windowCounter.unacknowledged},$bufferSize")
-  }
-
-  override fun receivingConnectionWindowChanged(windowCounter: WindowCounter) {
-    println("${System.currentTimeMillis() - start},0,${windowCounter.unacknowledged},")
-  }
-}