Fix for 6867515 added "D3D preload" feature.
Currently it includes creation of "main" Direct3D object (IDirect3D9)
Additional research shown that 2nd delay in D3D initialization occurs on creation/initialization of D3D Adapter objects (implemented in D3DContext class).
This delay becomes longer when D3D Adapter are created after some period of time after IDirect3D9 creation and this fact causes decreasing of performance improvement due D3D preload (for example plugins require more time for initializetion and in this case time period between IDirect3D9 creation & D3DAdapter creation often is too big).
D3DPipelineManager supports caching of D3DContext (when D3DContext for some adapter is requested, D3DPipelineManager returns existing object if it was created before), so we can do creation/initialization of D3DContext objects during preloading.