diff -r 000000000000 -r 6474c204b198 widget/gonk/Framebuffer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widget/gonk/Framebuffer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* Copyright 2012 Mozilla Foundation and Mozilla contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class gfxASurface;
+class nsIntRegion;
+class nsIntSize;
+
+namespace mozilla {
+
+namespace Framebuffer {
+
+//
+// The general usage of Framebuffer is
+//
+// -- in initialization code --
+//  Open();
+//
+// -- ready to paint next frame --
+//  nsRefPtr<gfxASurface> backBuffer = BackBuffer();
+//  // ...
+//  Paint(backBuffer);
+//  // ...
+//  Present();
+//
+
+// Return true if the fbdev was successfully opened.  If this fails, 
+// the result of all further calls is undefined.  Open() is idempotent.
+bool Open();
+
+// After Close(), the result of all further calls is undefined.
+// Close() is idempotent, and Open() can be called again after
+// Close().
+void Close();
+
+// Return true if the fbdev was successfully opened or the size was
+// already cached.
+bool GetSize(nsIntSize *aScreenSize);
+
+// Return the buffer to be drawn into, that will be the next frame.
+gfxASurface* BackBuffer();
+
+// Swap the front buffer for the back buffer.  |aUpdated| is the
+// region of the back buffer that was repainted.
+void Present(const nsIntRegion& aUpdated);
+
+} // namespace Framebuffer
+
+} // namespace mozilla