Declarative content scripts: Renderer-side: per-extension shared memory regions (lazily loaded)

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 307ce592ed7ed2577588901af91d8ff8739ad410..ca9f38fada4699d20265a51a64b8f6abcfe3e749 100644
--- a/extensions/common/extension_messages.h
+++ b/extensions/common/extension_messages.h
@@ -381,10 +381,15 @@ IPC_MESSAGE_ROUTED1(ExtensionMsg_ExecuteCode,
 // Notification that the user scripts have been updated. It has one
 // SharedMemoryHandle argument consisting of the pickled script data. This
 // handle is valid in the context of the renderer.
+// If |owner| is not empty, then the shared memory handle refers to |owner|'s

[Jeffrey Yasskin, 2014/07/28 17:47:15]

In this case, is |changed extensions| ignored, or must it either be empty or
contain exactly |owner|?

[Mark Dittmer, 2014/07/28 22:21:28]

|owner| indicates the extension associated with the shared memory object. That
is, it is the key for looking up the correct memory object. The semantics of
|changed_extensions| are the same; any extension that is known to be changed
should be listed.

As it turns out, messages with owner != "" will have exactly one extension
listed in |changed_extensions|. The only context in which owner != "" is a
context in which we wish to notify that the owner extension (and no other
extension) has changed.

+// programmatically defined scripts. Otherwise, the handle refers to all
+// extensions' statically defined scripts.
 // If |changed_extensions| is not empty, only the extensions in that set will
-// be updated. Otherwise, all extensions will be updated.
-IPC_MESSAGE_CONTROL2(ExtensionMsg_UpdateUserScripts,
+// be updated. Otherwise, all extensions that have scripts in the shared memory
+// region will be updated.
+IPC_MESSAGE_CONTROL3(ExtensionMsg_UpdateUserScripts,
                      base::SharedMemoryHandle,
+                     extensions::ExtensionId /* owner */,
                      std::set<std::string> /* changed extensions */)
 
 // Tell the render view which browser window it's being attached to.