[extension SW]: Support event listener registration and event dispatching.

extensions/renderer/worker_thread_dispatcher.cc

Index: extensions/renderer/worker_thread_dispatcher.cc
diff --git a/extensions/renderer/worker_thread_dispatcher.cc b/extensions/renderer/worker_thread_dispatcher.cc
index f338575218530f920d8bd0acc06c3db8409cf07c..35d71c1174634b49ad2e05862966bbf93f07b839 100644
--- a/extensions/renderer/worker_thread_dispatcher.cc
+++ b/extensions/renderer/worker_thread_dispatcher.cc
@@ -12,6 +12,7 @@
 #include "content/public/renderer/render_thread.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/feature_switch.h"
+#include "extensions/renderer/dispatcher.h"
 #include "extensions/renderer/extension_bindings_system.h"
 #include "extensions/renderer/js_extension_bindings_system.h"
 #include "extensions/renderer/native_extension_bindings_system.h"
@@ -86,7 +87,8 @@ V8SchemaRegistry* WorkerThreadDispatcher::GetV8SchemaRegistry() {
 // static
 bool WorkerThreadDispatcher::HandlesMessageOnWorkerThread(
     const IPC::Message& message) {
-  return message.type() == ExtensionMsg_ResponseWorker::ID;
+  return message.type() == ExtensionMsg_ResponseWorker::ID ||
+         message.type() == ExtensionMsg_DispatchEvent::ID;
 }
 
 // static
@@ -101,7 +103,8 @@ bool WorkerThreadDispatcher::OnControlMessageReceived(
   if (HandlesMessageOnWorkerThread(message)) {
     int worker_thread_id = base::kInvalidThreadId;
     bool found = base::PickleIterator(message).ReadInt(&worker_thread_id);

[dcheng, 2017/06/06 04:55:07]

Btw this seems pretty hard to understand. We should be able to assume this field
always exists right? This was previously a CHECK. Maybe this should be a routed
IPC...?

(A followup is OK for trying to make this routed, but in the short-term, it
seems like DCHECK(found)/CHECK(found) should be a reasonable thing to do still)

[lazyboy, 2017/06/06 19:12:00]

Yes, restored CHECK.
This was previously a CHECK. Maybe this should be a routed
Can we send a routed message to a child thread directly? This pattern is
borrowed from content/'s service worker code, e.g.
https://cs.chromium.org/chromium/src/content/child/worker_thread_message_filt...
We need to be able to pick the thread id to be able to dispatch the IPC to that
thread.

[dcheng, 2017/06/06 20:59:55]

Something something mojo I think. But in principle, there's no reason it
shouldn't be possible--fundamentally routable messages are just about unpickling
a known routing ID and then dispatching based off that.

-    CHECK(found && worker_thread_id > 0);
+    if (!found || worker_thread_id <= 0)

[dcheng, 2017/06/05 20:23:15]

Why would the worker_thread_id be < 0? Maybe just explicitly check for
worker_thread_id == kNonWorkerThreadId?

[lazyboy, 2017/06/05 21:12:06]

Done.

+      return false;
     base::TaskRunner* runner = GetTaskRunnerFor(worker_thread_id);
     bool task_posted = runner->PostTask(
         FROM_HERE, base::Bind(&WorkerThreadDispatcher::ForwardIPC,
@@ -119,6 +122,7 @@ void WorkerThreadDispatcher::OnMessageReceivedOnWorkerThread(
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(WorkerThreadDispatcher, message)
     IPC_MESSAGE_HANDLER(ExtensionMsg_ResponseWorker, OnResponseWorker)
+    IPC_MESSAGE_HANDLER(ExtensionMsg_DispatchEvent, OnDispatchEvent)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   CHECK(handled);
@@ -149,8 +153,18 @@ void WorkerThreadDispatcher::OnResponseWorker(int worker_thread_id,
       error);
 }
 
+void WorkerThreadDispatcher::OnDispatchEvent(
+    const ExtensionMsg_DispatchEvent_Params& params,
+    const base::ListValue& event_args) {
+  ServiceWorkerData* data = g_data_tls.Pointer()->Get();
+  DCHECK(data);
+  data->bindings_system()->DispatchEventInContext(
+      params.event_name, &event_args, &params.filtering_info, data->context());
+}
+
 void WorkerThreadDispatcher::AddWorkerData(
     int64_t service_worker_version_id,
+    ScriptContext* context,
     ResourceBundleSourceMap* source_map) {
   ServiceWorkerData* data = g_data_tls.Pointer()->Get();
   if (!data) {
@@ -164,7 +178,7 @@ void WorkerThreadDispatcher::AddWorkerData(
                           this, service_worker_version_id));
     }
     ServiceWorkerData* new_data = new ServiceWorkerData(
-        service_worker_version_id, std::move(bindings_system));
+        service_worker_version_id, context, std::move(bindings_system));
     g_data_tls.Pointer()->Set(new_data);
   }