Batch debug events sent from injected client to dwds (#1487)

* Batch debug events from injected client to dwds

Flutter framework sends frequent frame events using
`developer.postEvent`. In scenarios where we have to
use SSE between the browser and dwds this leads to
hign network load and slows down debugging.

Batch and send debug events every 1000ms instead.

Closes: #1466

* Updated webdev to run with the current dwds, build

* Update analyzer version to remove build warning

* Resolved merge conflict

* Update parsing libraries.json

* Fix BatcheStreamController.close() not terminating

* Addressed CR comments

* Build

* Addressed CR comments

Author: Anna Gringauze

dwds/CHANGELOG.md

@@ -11,6 +11,8 @@
 - Remove dead code for reading `'dart.developer.registerExtension'` and
   `'dart.developer.postEvent'` events from the chrome console. These messages
   haven't been written to the console since dwds v11.1.0 and Dart SDK v2.14.0.
+- Batch debug events sent from injected client to dwds to relieve network load. 
+- Update `_fe_analyzer_shared` version to `33.0.0`
 
 **Breaking changes:**
 

dwds/lib/data/debug_event.dart

@@ -4,6 +4,7 @@
 
 // @dart = 2.9
 
+import 'package:built_collection/built_collection.dart';
 import 'package:built_value/built_value.dart';
 import 'package:built_value/serializer.dart';
 
@@ -22,3 +23,17 @@ abstract class DebugEvent implements Built<DebugEvent, DebugEventBuilder> {
 
   int get timestamp;
 }
+
+/// A batched group of events, currently always Debugger.scriptParsed
+abstract class BatchedDebugEvents
+    implements Built<BatchedDebugEvents, BatchedDebugEventsBuilder> {
+  static Serializer<BatchedDebugEvents> get serializer =>
+      _$batchedDebugEventsSerializer;
+
+  factory BatchedDebugEvents([Function(BatchedDebugEventsBuilder) updates]) =
+      _$BatchedDebugEvents;
+
+  BatchedDebugEvents._();
+
+  BuiltList<DebugEvent> get events;
+}

dwds/lib/data/debug_event.g.dart

@@ -22,6 +22,7 @@ part 'serializers.g.dart';
 /// Serializers for all the types used in DWDS communication.
 @SerializersFor([
   BatchedEvents,
+  BatchedDebugEvents,
   BuildResult,
   ConnectRequest,
   DebugEvent,

dwds/lib/data/serializers.dart

@@ -266,6 +266,10 @@ class DevHandler {
             await _handleIsolateExit(appConnection);
           } else if (message is IsolateStart) {
             await _handleIsolateStart(appConnection, injectedConnection);
+          } else if (message is BatchedDebugEvents) {
+            await _servicesByAppId[appConnection.request.appId]
+                ?.chromeProxyService
+                ?.parseBatchedDebugEvents(message);
           } else if (message is DebugEvent) {
             await _servicesByAppId[appConnection.request.appId]
                 ?.chromeProxyService