Adds makeSwapChain9/11 functions.

TRAC #22134

Signed-off-by: Nicolas Capens
Signed-off-by: Daniel Koch

git-svn-id: https://angleproject.googlecode.com/svn/branches/dx11proto@1477 736b8ea6-26fd-11df-bfd4-992fa37f6226
diff --git a/src/libGLESv2/renderer/SwapChain9.cpp b/src/libGLESv2/renderer/SwapChain9.cpp
index 4e1fa04..069e65c 100644
--- a/src/libGLESv2/renderer/SwapChain9.cpp
+++ b/src/libGLESv2/renderer/SwapChain9.cpp
@@ -395,4 +395,10 @@
     return mOffscreenTexture;
 }
 
+SwapChain9 *SwapChain9::makeSwapChain9(SwapChain *swapChain)
+{
+    ASSERT(dynamic_cast<rx::SwapChain9*>(swapChain) != NULL);
+    return static_cast<rx::SwapChain9*>(swapChain);
+}
+
 }