Bug 1097464 - Part 1 - Remove Z value from 3D transforms for D3D9. r=roc,matt.woodrow

--HG--
extra : rebase_source : 3ff8f50daf2309dd742806ab34577acc8edf38c7

gfx/layers/d3d9/CompositorD3D9.cpp

@@ -692,6 +692,7 @@ CompositorD3D9::PrepareViewport(const gfx::IntSize& aSize)
   viewMatrix._22 = -2.0f / aSize.height;
   viewMatrix._41 = -1.0f;
   viewMatrix._42 = 1.0f;
+  viewMatrix._33 = 0.0f;
 
   HRESULT hr = device()->SetVertexShaderConstantF(CBmProjection, &viewMatrix._11, 4);