Fix device_event_log component build, make NonThreadSafe (Take 2)

components/device_event_log/device_event_log_export.h

Index: components/device_event_log/device_event_log_export.h
diff --git a/components/device_event_log/device_event_log_export.h b/components/device_event_log/device_event_log_export.h
new file mode 100644
index 0000000000000000000000000000000000000000..c693b74aa216538ba04f6633ae2d3b30112b4804
--- /dev/null
+++ b/components/device_event_log/device_event_log_export.h
@@ -0,0 +1,34 @@
+// 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_DEVICE_EVENT_LOG_DEVICE_EVENT_LOG_EXPORT_H_
+#define COMPONENTS_DEVICE_EVENT_LOG_DEVICE_EVENT_LOG_EXPORT_H_
+
+#if defined(COMPONENT_BUILD)
+
+#if defined(WIN32)
+
+#if defined(DEVICE_EVENT_LOG_IMPLEMENTATION)
+#define DEVICE_EVENT_LOG_EXPORT __declspec(dllexport)
+#else
+#define DEVICE_EVENT_LOG_EXPORT __declspec(dllimport)
+#endif  // defined(DEVICE_EVENT_LOG_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+
+#if defined(DEVICE_EVENT_LOG_IMPLEMENTATION)
+#define DEVICE_EVENT_LOG_EXPORT __attribute__((visibility("default")))
+#else
+#define DEVICE_EVENT_LOG_EXPORT
+#endif  // defined(DEVICE_EVENT_LOG_IMPLEMENTATION)
+
+#endif  // defined(WIN32)
+
+#else  // defined(COMPONENT_BUILD)
+
+#define DEVICE_EVENT_LOG_EXPORT
+
+#endif
+
+#endif  // COMPONENTS_DEVICE_EVENT_LOG_DEVICE_EVENT_LOG_EXPORT_H_