Add an IPC method for Blink to call RapporService::RecordSample()

components/rappor/rappor_message_filter.cc

Index: components/rappor/rappor_message_filter.cc
diff --git a/components/rappor/rappor_message_filter.cc b/components/rappor/rappor_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..077cc57d6ad4c6b4d2c68cb85c5513f8dd3e5f68
--- /dev/null
+++ b/components/rappor/rappor_message_filter.cc
@@ -0,0 +1,51 @@
+// Copyright (c) 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.
+
+#include "components/rappor/rappor_message_filter.h"
+
+#include "components/rappor/rappor_messages.h"
+#include "components/rappor/rappor_service.h"
+#include "components/rappor/rappor_utils.h"
+#include "ipc/ipc_message_macros.h"
+
+using content::BrowserThread;
+
+namespace rappor {
+
+RapporMessageFilter::RapporMessageFilter(RapporService* rapporService)
+    : BrowserMessageFilter(RapporMsgStart),
+      m_rapporService(rapporService) {
+  DCHECK(rapporService);
+}
+
+RapporMessageFilter::~RapporMessageFilter() {}
+
+void RapporMessageFilter::OverrideThreadForMessage(
+    const IPC::Message& message, BrowserThread::ID* thread) {
+  switch (message.type()) {
+  case RapporHostMsg_RecordSample::ID:
+    *thread = BrowserThread::UI;
+    break;
+  }
+}
+
+bool RapporMessageFilter::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(RapporMessageFilter, message)
+    IPC_MESSAGE_HANDLER(RapporHostMsg_RecordSample, OnRecordSample)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void RapporMessageFilter::OnRecordSample(
+    const std::string& metric,
+    const std::string& sample) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  m_rapporService->RecordSample(metric,
+                                rappor::ETLD_PLUS_ONE_RAPPOR_TYPE,
+                                sample);
+}
+
+}  // namespace rappor