Create vector icon resource directory specific to Chrome.

chrome/app/vector_icons/vector_icons.h.template

Index: chrome/app/vector_icons/vector_icons.h.template
diff --git a/chrome/app/vector_icons/vector_icons.h.template b/chrome/app/vector_icons/vector_icons.h.template
new file mode 100644
index 0000000000000000000000000000000000000000..4bc81a728b75c46d05b344dadeff3663ee85b815
--- /dev/null
+++ b/chrome/app/vector_icons/vector_icons.h.template
@@ -0,0 +1,20 @@
+// Copyright 2017 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.
+
+// vector_icons.h.template is used to generate vector_icons.h. Edit the former
+// rather than the latter.
+
+#ifndef CHROME_APP_VECTOR_ICONS_VECTOR_ICONS_H_
+#define CHROME_APP_VECTOR_ICONS_VECTOR_ICONS_H_
+
+namespace gfx {
+struct VectorIcon;
+}
+
+#define VECTOR_ICON_TEMPLATE_H(icon_name) \
+extern const gfx::VectorIcon icon_name;
+
+TEMPLATE_PLACEHOLDER
+
+#endif  // CHROME_APP_VECTOR_ICONS_VECTOR_ICONS_H_