Introduce bad_message.h for chrome and NaCl.

components/nacl/browser/bad_message.h

Index: components/nacl/browser/bad_message.h
diff --git a/extensions/browser/bad_message.h b/components/nacl/browser/bad_message.h
similarity index 50%
copy from extensions/browser/bad_message.h
copy to components/nacl/browser/bad_message.h
index ab26aba6a3b3bfd21aa5a7b4340f4177dd150407..0a7ceb20709c3087ef0e21e106a51e032bd4123a 100644
--- a/extensions/browser/bad_message.h
+++ b/components/nacl/browser/bad_message.h
@@ -1,43 +1,43 @@
-// Copyright 2015 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.
-
-#ifndef EXTENSIONS_BROWSER_BAD_MESSAGE_H_
-#define EXTENSIONS_BROWSER_BAD_MESSAGE_H_
-
-namespace content {
-class RenderProcessHost;
-}
-
-namespace extensions {
-namespace bad_message {
-
-// The browser process often chooses to terminate a renderer if it receives
-// a bad IPC message. The reasons are tracked for metrics.
-//
-// See also content/browser/bad_message.h.
-//
-// NOTE: Do not remove or reorder elements in this list. Add new entries at the
-// end. Items may be renamed but do not change the values. We rely on the enum
-// values in histograms. Also update histograms.xml with any new values.
-enum BadMessageReason {
-  EOG_BAD_ORIGIN = 0,
-  EVG_BAD_ORIGIN = 1,
-  BH_BLOB_NOT_OWNED = 2,
-  EH_BAD_EVENT_ID = 3,
-  // Please add new elements here. The naming convention is abbreviated class
-  // name (e.g. ExtensionHost becomes EH) plus a unique description of the
-  // reason.
-  BAD_MESSAGE_MAX
-};
-
-// Called when the browser receives a bad IPC message from an extension process.
-// Logs the event, records a histogram metric for the |reason|, and terminates
-// the process for |host|.
-void ReceivedBadMessage(content::RenderProcessHost* host,
-                        BadMessageReason reason);
-
-}  // bad_message
-}  // namespace extensions
-
-#endif  // EXTENSIONS_BROWSER_BAD_MESSAGE_H_
+// Copyright 2015 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.
+
+#ifndef COMPONENTS_NACL_BROWSER_BAD_MESSAGE_H_
+#define COMPONENTS_NACL_BROWSER_BAD_MESSAGE_H_
+
+namespace content {
+class BrowserMessageFilter;
+}
+
+namespace nacl {
+namespace bad_message {
+
+// The browser process often chooses to terminate a renderer if it receives
+// a bad IPC message. The reasons are tracked for metrics.
+//
+// See also content/browser/bad_message.h.
+//
+// NOTE: Do not remove or reorder elements in this list. Add new entries at the
+// end. Items may be renamed but do not change the values. We rely on the enum
+// values in histograms. Also update histograms.xml with any new values.
+enum BadMessageReason {
+  NFH_OPEN_EXECUTABLE_BAD_ROUTING_ID = 0,
+  NHMF_LAUNCH_CONTINUATION_BAD_ROUTING_ID = 1,
+  NHMF_GET_NEXE_FD_BAD_URL = 2,
+
+  // Please add new elements here. The naming convention is abbreviated class
+  // name (e.g. NaclHostMessageFilter becomes NHMF) plus a unique description of

[Mark Seaborn, 2015/05/27 11:50:33]

What does "NFH" stand for?  Is it nacl_file_host.cc?  Nit: that's not a class
name.

Are these prefixes supposed to get renamed if the file reporting the error gets
renamed?

[ncarter (slow), 2015/06/01 19:08:11]

I think the point of these is partially mnemonic, and partially to avoid
namespace collisions if two different files handle the same kind of error. NFH
isn't structured as a class, but it is a name that indicates which filename is
better.

I had these as NACL_ in a previous patchset and changed them to NHMF_ based on
Charlie pointing out that it was inconsistent with the pattern used elsewhere. I
had them as NACL_ originally because nacl_file_host wasn't a class name and I
didn't know what else to do. The collision issue seems less likely here, since
this component is so much smaller than the others.

Mark -- are you okay with NFH_ or should I switch back to NACL_ or something
else?

[ncarter (slow), 2015/06/01 19:09:41]

"which filename is better" made no sense -- I meant, NFH gave you an indication
of where to look.

+  // the reason.
+  BAD_MESSAGE_MAX
+};
+
+// Called when a browser message filter receives a bad IPC message from a
+// renderer or other child process. Logs the event, records a histogram metric

[Mark Seaborn, 2015/05/27 11:50:33]

This says "renderer or other child process".  The text above says "renderer". 
components/nacl/browser/bad_message.cc says "renderer".  Can you make this
consistent?

Currently this is only called to terminate the renderer, so you could drop "or
other child process" for now.

[ncarter (slow), 2015/06/01 19:08:11]

A RenderProcessHost implies it's a renderer process. A BrowserMessageFilter
could be created for renderer or non-renderer child processes, hence this
language.

+// for the |reason|, and terminates the process for |filter|.
+void ReceivedBadMessage(content::BrowserMessageFilter* filter,
+                        BadMessageReason reason);
+
+}  // namespace bad_message
+}  // namespace nacl
+
+#endif  // COMPONENTS_NACL_BROWSER_BAD_MESSAGE_H_