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

components/rappor/rappor_message_filter.h

Index: components/rappor/rappor_message_filter.h
diff --git a/components/rappor/rappor_message_filter.h b/components/rappor/rappor_message_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..fdf06a48715122f0f9b1a736569640f3dbfe957e
--- /dev/null
+++ b/components/rappor/rappor_message_filter.h
@@ -0,0 +1,39 @@
+// 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.
+
+#ifndef COMPONENTS_RAPPOR_RAPPOR_MESSAGE_FILTER_H_
+#define COMPONENTS_RAPPOR_RAPPOR_MESSAGE_FILTER_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/macros.h"
+#include "content/public/browser/browser_message_filter.h"
+
+namespace rappor {
+
+class RapporService;
+
+// This class sends and receives trace messages on child processes.
+class RapporMessageFilter : public content::BrowserMessageFilter {
+ public:
+  explicit RapporMessageFilter(RapporService*);
+
+  void OverrideThreadForMessage(const IPC::Message& message,
+                                content::BrowserThread::ID* thread) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
+
+ private:
+  ~RapporMessageFilter() override;
+
+  void OnRecordSample(const std::string&, const std::string&);
+
+  RapporService* m_rapporService;
+
+  DISALLOW_COPY_AND_ASSIGN(RapporMessageFilter);
+};
+
+}  // namespace rappor
+
+#endif  // COMPONENTS_RAPPOR_RAPPOR_MESSAGE_FILTER_H_