remove channel from pool with pointer rather than config

src/objective-c/GRPCClient/private/GRPCChannel.m

@@ -204,7 +204,7 @@ NSTimeInterval kChannelDestroyDelay = 30;
     if (self->_unmanagedChannel) {
       grpc_channel_destroy(self->_unmanagedChannel);
       self->_unmanagedChannel = nil;
-      [gChannelPool removeChannelWithConfiguration:self->_configuration];
+      [gChannelPool removeChannel:self];
     }
   });
 }

src/objective-c/GRPCClient/private/GRPCChannelPool.h

@@ -55,8 +55,8 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (GRPCChannel *)channelWithConfiguration:(GRPCChannelConfiguration *)configuration;
 
-/** Remove a channel with particular configuration. */
+/** Remove a channel from the pool. */
-- (void)removeChannelWithConfiguration:(GRPCChannelConfiguration *)configuration;
+- (void)removeChannel:(GRPCChannel *)channel;
 
 /** Clear all channels in the pool. */
 - (void)removeAllChannels;

src/objective-c/GRPCClient/private/GRPCChannelPool.m

@@ -199,9 +199,13 @@ extern const char *kCFStreamVarName;
   return channel;
 }
 
-- (void)removeChannelWithConfiguration:(GRPCChannelConfiguration *)configuration {
+- (void)removeChannel:(GRPCChannel *)channel {
   @synchronized(self) {
-    [self->_channelPool removeObjectForKey:configuration];
+    [_channelPool enumerateKeysAndObjectsUsingBlock:^(GRPCChannelConfiguration * _Nonnull key, GRPCChannel * _Nonnull obj, BOOL * _Nonnull stop) {
+      if (obj == channel) {
+        [self->_channelPool removeObjectForKey:key];
+      }
+    }];
   }
 }
 

src/objective-c/tests/ChannelTests/ChannelPoolTest.m

@@ -59,7 +59,7 @@ NSString *kDummyHost = @"dummy.host";
   GRPCChannelPool *pool = [[GRPCChannelPool alloc] init];
   GRPCChannel *channel1 =
       [pool channelWithConfiguration:config1];
-  [pool removeChannelWithConfiguration:config1];
+  [pool removeChannel:channel1];
   GRPCChannel *channel2 =
       [pool channelWithConfiguration:config1];
   XCTAssertNotEqual(channel1, channel2);