Delete blimp/helium and remove references to it from dependent targets

blimp/helium/blimp_helium_export.h

Index: blimp/helium/blimp_helium_export.h
diff --git a/blimp/helium/blimp_helium_export.h b/blimp/helium/blimp_helium_export.h
deleted file mode 100644
index 27fbd2d19bfb73836b9c5cd27407155bb9a0d70b..0000000000000000000000000000000000000000
--- a/blimp/helium/blimp_helium_export.h
+++ /dev/null
@@ -1,29 +0,0 @@
-// 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 BLIMP_HELIUM_BLIMP_HELIUM_EXPORT_H_
-#define BLIMP_HELIUM_BLIMP_HELIUM_EXPORT_H_
-
-#if defined(COMPONENT_BUILD)
-#if defined(WIN32)
-
-#if defined(HELIUM_IMPLEMENTATION)
-#define BLIMP_HELIUM_EXPORT __declspec(dllexport)
-#else
-#define BLIMP_HELIUM_EXPORT __declspec(dllimport)
-#endif  // defined(HELIUM_IMPLEMENTATION)
-
-#else  // defined(WIN32)
-#if defined(HELIUM_IMPLEMENTATION)
-#define BLIMP_HELIUM_EXPORT __attribute__((visibility("default")))
-#else
-#define BLIMP_HELIUM_EXPORT
-#endif  // defined(HELIUM_IMPLEMENTATION)
-#endif
-
-#else  // defined(COMPONENT_BUILD)
-#define BLIMP_HELIUM_EXPORT
-#endif
-
-#endif  // BLIMP_HELIUM_BLIMP_HELIUM_EXPORT_H_