Move flash clipboard to the new proxy and add custom format support

ppapi/thunk/ppb_flash_clipboard_api.h

Index: ppapi/thunk/ppb_flash_clipboard_api.h
diff --git a/ppapi/thunk/ppb_flash_clipboard_api.h b/ppapi/thunk/ppb_flash_clipboard_api.h
new file mode 100644
index 0000000000000000000000000000000000000000..ef022c4a7c17cb7c94ccb870dd5796b0ca138fb4
--- /dev/null
+++ b/ppapi/thunk/ppb_flash_clipboard_api.h
@@ -0,0 +1,40 @@
+// 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 PPAPI_THUNK_PPB_FLASH_CLIPBOARD_API_H_
+#define PPAPI_THUNK_PPB_FLASH_CLIPBOARD_API_H_
+
+#include "ppapi/c/private/ppb_flash_clipboard.h"
+
+namespace ppapi {
+namespace thunk {
+
+class PPB_Flash_Clipboard_API {
+ public:
+  virtual ~PPB_Flash_Clipboard_API() {}
+
+  // PPB_Flash_Clipboard.
+  virtual uint32_t RegisterCustomFormat(
+    PP_Instance instance,
+    const char* format_name) = 0;
+  virtual PP_Bool IsFormatAvailable(
+    PP_Instance instance,
+    PP_Flash_Clipboard_Type clipboard_type,
+    uint32_t format) = 0;
+  virtual PP_Var ReadData(
+    PP_Instance instance,
+    PP_Flash_Clipboard_Type clipboard_type,
+    uint32_t format) = 0;
+  virtual int32_t WriteData(
+    PP_Instance instance,
+    PP_Flash_Clipboard_Type clipboard_type,
+    uint32_t data_item_count,
+    const uint32_t formats[],
+    const PP_Var data_items[]) = 0;
+};
+
+}  // namespace thunk
+}  // namespace ppapi
+
+#endif // PPAPI_THUNK_PPB_FLASH_CLIPBOARD_API_H_