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 904c2f98b42ee2e154b2971bd3c5e0ebeeb8f0cf..e588bb4397e1217a98c5a51f24199ee436cdaadd 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.
@@ -571,6 +579,12 @@ IPC_MESSAGE_ROUTED2(ExtensionMsg_DispatchOnDisconnect,
 IPC_MESSAGE_CONTROL1(ExtensionMsg_SetChannel,
                      int /* channel */)
 
+// Informs the renderer whether extension APIs should be enabled in extension
+// service worker contexts.
+IPC_MESSAGE_CONTROL1(
+    ExtensionMsg_SetExtensionAPIEnabledInExtensionServiceWorkers,
+    bool /* enabled */)

[Devlin, 2016/04/14 22:34:52]

Maybe we should just enable this on trunk.  For one thing, then we only need the
SetChannel IPC above.  For another, it means that we get trybot coverage for all
of this - which is good.

[lazyboy, 2016/04/15 00:57:47]

OK, moved the feature thing to ExtensionsClient.

+
 // Notify the renderer that its window has closed.
 IPC_MESSAGE_ROUTED0(ExtensionMsg_AppWindowClosed)
 
@@ -831,3 +845,22 @@ 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 */)