Add onBytesReceived callback to consolidateHttpClientResponseBytes() (#32853)

This will allow us to plumb the chunks in a chunked response
up to the higher levels of the framework to notify interested
parties of network loading progress.

https://github.com/flutter/flutter/issues/32374
https://dart.googlesource.com/external/github.com/flutter/flutter/+/8eb7b729266eb13b9163723ccd0c38179df5847c
diff --git a/commits.json b/commits.json
index b9aaae8..b23fa59 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
   "external/github.com/flutter/engine":"e40768c63a00252062ea1061a6db9e756ccb65e8",
-  "external/github.com/flutter/flutter":"2b15b244868e3dc89d1502150f7b4f319d3de7e7",
+  "external/github.com/flutter/flutter":"8eb7b729266eb13b9163723ccd0c38179df5847c",
   "sdk":"2a85d595ba5541c01d3fd8961c929f9ac4695597"
 }
\ No newline at end of file