Add UMA histograms and logging for bad IPC message handling

content/browser/bad_message.h

Index: content/browser/bad_message.h
diff --git a/content/browser/bad_message.h b/content/browser/bad_message.h
new file mode 100644
index 0000000000000000000000000000000000000000..00eae410e88e0aa5768efec6482733095de0efe4
--- /dev/null
+++ b/content/browser/bad_message.h
@@ -0,0 +1,55 @@
+// 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 CONTENT_BROWSER_BAD_MESSAGE_H_
+#define CONTENT_BROWSER_BAD_MESSAGE_H_
+
+namespace content {
+class RenderProcessHost;
+
+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.
+//
+// Content embedders should implement their own bad message statistics but
+// should use similar histogram names to make analysis easier.
+//
+// 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.
+enum BadMessageReason {
+  NC_IN_PAGE_NAVIGATION = 0,
+  RFH_CAN_COMMIT_URL_BLOCKED,
+  RFH_CAN_ACCESS_FILES_OF_PAGE_STATE,
+  RFH_SANDBOX_FLAGS,
+  RFH_NO_PROXY_TO_PARENT,
+  RPH_DESERIALIZATION_FAILED,
+  RVH_CAN_ACCESS_FILES_OF_PAGE_STATE,
+  RVH_FILE_CHOOSER_PATH,
+  RWH_SYNTHETIC_GESTURE,
+  RWH_FOCUS,
+  RWH_BLUR,
+  RWH_SHARED_BITMAP,
+  RWH_BAD_ACK_MESSAGE,
+  RWHVA_SHARED_MEMORY,
+  SERVICE_WORKER_BAD_URL,
+  WC_INVALID_FRAME_SOURCE,
+  RWHVM_UNEXPECTED_FRAME_TYPE,
+  // Please add new elements here. The naming convention is abbreviated class
+  // name (e.g. RenderFrameHost becomes RFH) plus a unique description of the
+  // reason.
+

[Charlie Reis, 2015/03/19 04:01:49]

nit: s/here/above BAD_MESSAGE_MAX/
nit: Remove blank line.

[James Cook, 2015/03/19 16:19:11]

Done.

+  BAD_MESSAGE_MAX
+};
+
+// Called when the browser receives a bad IPC message from a renderer process.
+// Logs the event, records a histogram metric for the |reason|, and terminates
+// the process for |host|.
+void ReceivedBadMessage(RenderProcessHost* host, BadMessageReason reason);
+
+}  // namespace bad_message
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BAD_MESSAGE_H_