Fix ODR violations caused by mojoms being included in multiple components.

device/generic_sensor/public/cpp/generic_sensor_public_export.h

Index: device/generic_sensor/public/cpp/generic_sensor_public_export.h
diff --git a/device/generic_sensor/public/cpp/generic_sensor_public_export.h b/device/generic_sensor/public/cpp/generic_sensor_public_export.h
new file mode 100644
index 0000000000000000000000000000000000000000..fba050035c4c983d8abb4b6298d8c1b41ecba28c
--- /dev/null
+++ b/device/generic_sensor/public/cpp/generic_sensor_public_export.h
@@ -0,0 +1,30 @@
+// Copyright 2016 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 DEVICE_GENERIC_SENSOR_PUBLIC_CPP_GENERIC_SENSOR_PUBLIC_EXPORT_H_
+#define DEVICE_GENERIC_SENSOR_PUBLIC_CPP_GENERIC_SENSOR_PUBLIC_EXPORT_H_
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(DEVICE_GENERIC_SENSOR_PUBLIC_IMPLEMENTATION)
+#define DEVICE_GENERIC_SENSOR_PUBLIC_EXPORT __declspec(dllexport)
+#else
+#define DEVICE_GENERIC_SENSOR_PUBLIC_EXPORT __declspec(dllimport)
+#endif  // defined(DEVICE_GENERIC_SENSOR_PUBLIC_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(DEVICE_GENERIC_SENSOR_PUBLIC_IMPLEMENTATION)
+#define DEVICE_GENERIC_SENSOR_PUBLIC_EXPORT \
+  __attribute__((visibility("default")))
+#else
+#define DEVICE_GENERIC_SENSOR_PUBLIC_EXPORT
+#endif
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define DEVICE_GENERIC_SENSOR_PUBLIC_EXPORT
+#endif
+
+#endif  // DEVICE_GENERIC_SENSOR_PUBLIC_CPP_GENERIC_SENSOR_PUBLIC_EXPORT_H_