Relanding "views: Add a gyp file to build webview.". Try 2.

ui/views/controls/webview/webview_export.h

Index: ui/views/controls/webview/webview_export.h
diff --git a/ui/views/controls/webview/webview_export.h b/ui/views/controls/webview/webview_export.h
new file mode 100644
index 0000000000000000000000000000000000000000..2b071ccedc40fd5fb3cdd257df95021b5a2d6dbb
--- /dev/null
+++ b/ui/views/controls/webview/webview_export.h
@@ -0,0 +1,32 @@
+// Copyright (c) 2012 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 UI_VIEWS_CONTROLS_WEBVIEW_WEBVIEW_EXPORT_H_
+#define UI_VIEWS_CONTROLS_WEBVIEW_WEBVIEW_EXPORT_H_
+
+// Defines WEBVIEW_EXPORT so that functionality implemented by the webview
+// module can be exported to consumers.
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(WEBVIEW_IMPLEMENTATION)
+#define WEBVIEW_EXPORT __declspec(dllexport)
+#else
+#define WEBVIEW_EXPORT __declspec(dllimport)
+#endif  // defined(WEBVIEW_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(WEBVIEW_IMPLEMENTATION)
+#define WEBVIEW_EXPORT __attribute__((visibility("default")))
+#else
+#define WEBVIEW_EXPORT
+#endif
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define WEBVIEW_EXPORT
+#endif
+
+#endif  // UI_VIEWS_CONTROLS_WEBVIEW_WEBVIEW_EXPORT_H_