Convert components/tracing from static lib to component

components/tracing/tracing_export.h

Index: components/tracing/tracing_export.h
diff --git a/components/tracing/tracing_export.h b/components/tracing/tracing_export.h
new file mode 100644
index 0000000000000000000000000000000000000000..ac24e303bcd6189afef2756741ddbb3857959eac
--- /dev/null
+++ b/components/tracing/tracing_export.h
@@ -0,0 +1,29 @@
+// 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_TRACING_TRACING_EXPORT_H_
+#define COMPONENTS_TRACING_TRACING_EXPORT_H_
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(TRACING_IMPLEMENTATION)
+#define TRACING_EXPORT __declspec(dllexport)
+#else
+#define TRACING_EXPORT __declspec(dllimport)
+#endif  // defined(TRACING_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(TRACING_IMPLEMENTATION)
+#define TRACING_EXPORT __attribute__((visibility("default")))
+#else
+#define TRACING_EXPORT
+#endif // defined(TRACING_IMPLEMENTATION)
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define TRACING_EXPORT
+#endif
+
+#endif  // COMPONENTS_TRACING_TRACING_EXPORT_H_