Begin to enable extension APIs in Extension Service Worker.

extensions/common/extension_messages.h

 // Copyright 2014 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.
 
 // IPC messages for extensions.
 // Multiply-included message file, hence no include guard.
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 88 matching lines @@
   IPC_STRUCT_MEMBER(int, source_tab_id)
 
   // Unique request id to match requests and responses.
   IPC_STRUCT_MEMBER(int, request_id)
 
   // True if request has a callback specified.
   IPC_STRUCT_MEMBER(bool, has_callback)
 
   // True if request is executed in response to an explicit user gesture.
   IPC_STRUCT_MEMBER(bool, user_gesture)
+
+  // If this API call is for a service worker, then this is the worker thread
+  // id.

[Devlin, 2016/04/13 19:46:31]

Otherwise, this is...?

[lazyboy, 2016/04/14 02:07:53]

Done.

+  IPC_STRUCT_MEMBER(int, worker_thread_id)
+
+  // If this API call is for a service worker, then this is the embedded
+  // worker id.

[Devlin, 2016/04/13 19:46:31]

ditto

[lazyboy, 2016/04/14 02:07:53]

Done.

+  IPC_STRUCT_MEMBER(int, embedded_worker_id)
 IPC_STRUCT_END()
 
 // Allows an extension to execute code in a tab.
 IPC_STRUCT_BEGIN(ExtensionMsg_ExecuteCode_Params)
   // The extension API request id, for responding.
   IPC_STRUCT_MEMBER(int, request_id)
 
   // The ID of the requesting injection host.
   IPC_STRUCT_MEMBER(HostID, host_id)
 
@@ skipping 705 matching lines @@
                     int /* acc_obj_id */,
                     base::string16 /* selector */)
 
 // Result of a query selector request.
 // result_acc_obj_id is the accessibility tree ID of the result element; 0
 // indicates no result.
 IPC_MESSAGE_ROUTED3(ExtensionHostMsg_AutomationQuerySelector_Result,
                     int /* request_id */,
                     ExtensionHostMsg_AutomationQuerySelector_Error /* error */,
                     int /* result_acc_obj_id */)
+
+// Messages related to Extension Service Worker.
+#undef IPC_MESSAGE_START
+#define IPC_MESSAGE_START ExtensionWorkerMsgStart
+// A service worker thread sends this message when an extension service worker
+// starts an API request. The browser will always respond with a
+// ExtensionMsg_ResponseWorker.
+IPC_MESSAGE_CONTROL1(ExtensionHostMsg_RequestWorker,
+                     ExtensionHostMsg_Request_Params)
+
+// The browser sends this message in response to all service worker extension
+// api calls. The response data (if any) is one of the base::Value subclasses,
+// wrapped as the first element in a ListValue.
+IPC_MESSAGE_CONTROL5(ExtensionMsg_ResponseWorker,
+                     int /* thread_id */,
+                     int /* request_id */,
+                     bool /* success */,
+                     base::ListValue /* response wrapper (see comment above) */,
+                     std::string /* error */)