Implement out-of-process proxy for PPB_Buffer_Dev.

ppapi/c/trusted/ppb_buffer_trusted.h

Index: ppapi/c/trusted/ppb_buffer_trusted.h
diff --git a/ppapi/c/trusted/ppb_buffer_trusted.h b/ppapi/c/trusted/ppb_buffer_trusted.h
new file mode 100644
index 0000000000000000000000000000000000000000..d8568c5dd33ce3cdc9efd54e0857bb32cbe8e105
--- /dev/null
+++ b/ppapi/c/trusted/ppb_buffer_trusted.h
@@ -0,0 +1,24 @@
+/* Copyright (c) 2011 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_C_TRUSTED_PPB_BUFFER_TRUSTED_H_
+#define PPAPI_C_TRUSTED_PPB_BUFFER_TRUSTED_H_
+
+#include "ppapi/c/pp_stdint.h"
+#include "ppapi/c/pp_resource.h"
+
+#define PPB_BUFFER_TRUSTED_INTERFACE "PPB_BufferTrusted;0.1"
+
+struct PPB_BufferTrusted {
+  /**
+   * Returns the internal shared memory pointer associated with the given
+   * Buffer resource.  Used for proxying.  Returns PP_OK on success, or
+   * PP_ERROR_* on failure.  On success, the size in bytes of the shared
+   * memory region will be placed into |*byte_count|, and the handle for
+   * the shared memory in |*handle|.
+   */
+  int32_t (*GetSharedMemory)(PP_Resource buffer, int* handle);
+};
+
+#endif  // PPAPI_C_TRUSTED_PPB_BUFFER_TRUSTED_H_