Fix TabSocket.onmessage whoch should be able to retrieve all messages

headless/lib/renderer/headless_content_renderer_client.cc

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "headless/lib/renderer/headless_content_renderer_client.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/common/bindings_policy.h"
 #include "content/public/common/isolated_world_ids.h"
@@ skipping 98 matching lines @@
     v8::Isolate* isolate = blink::MainThreadIsolate();
     v8::HandleScope handle_scope(isolate);
     v8::Local<v8::Context> context = GetContext();
     v8::Local<v8::Value> argv[] = {
         gin::Converter<std::string>::ToV8(isolate, message),
     };
 
     render_frame()->GetWebFrame()->RequestExecuteV8Function(
         context, GetOnMessageCallback(), context->Global(), arraysize(argv),
         argv, this);
+
+    EnsureTabSocketPtr()->AwaitNextMessageFromEmbedder(
+        base::Bind(&HeadlessTabSocketBindings::OnNextMessageFromEmbedder,
+                   weak_ptr_factory_.GetWeakPtr()));
   }
 
   void InitializeTabSocketBindings(v8::Local<v8::Context> context) {
     // Add TabSocket bindings to the DevTools created isolated world.
     v8::Isolate* isolate = blink::MainThreadIsolate();
     v8::HandleScope handle_scope(isolate);
     if (context.IsEmpty())
       return;
 
     v8::Context::Scope context_scope(context);
@@ skipping 36 matching lines @@
 void HeadlessContentRendererClient::RenderFrameCreated(
     content::RenderFrame* render_frame) {
 #if BUILDFLAG(ENABLE_BASIC_PRINTING)
   new printing::PrintWebViewHelper(
       render_frame, base::MakeUnique<HeadlessPrintWebViewHelperDelegate>());
 #endif
   new HeadlessTabSocketBindings(render_frame);
 }
 
 }  // namespace headless