Begin to enable extension APIs in Extension Service Worker.

extensions/common/extension_messages.h

Index: extensions/common/extension_messages.h
diff --git a/extensions/common/extension_messages.h b/extensions/common/extension_messages.h
index bd48626c3e630750bfbfbfd7e36ae4a7d565e330..fe06a71ccdf0527a1893f05b8a2c1751300e592f 100644
--- a/extensions/common/extension_messages.h
+++ b/extensions/common/extension_messages.h
@@ -106,6 +106,14 @@ IPC_STRUCT_BEGIN(ExtensionHostMsg_Request_Params)
 
   // 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. Otherwise, this is -1.
+  IPC_STRUCT_MEMBER(int, worker_thread_id)
+
+  // If this API call is for a service worker, then this is the embedded
+  // worker id. Otherwise, this is -1.
+  IPC_STRUCT_MEMBER(int, embedded_worker_id)
 IPC_STRUCT_END()
 
 // Allows an extension to execute code in a tab.
@@ -838,3 +846,22 @@ 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 */)