Share one GLContext for all RasterDecoder when virtual context is used.

With this CL, we will create a GLContextVirtual in RasterDecoderContextState,
and share it with all raster decoders, display compositoer, etc. It is a
temporary solution. In follow up CLs, we will share the one GLContext with
GLES2 as well. In that case, we will use GLContext directly instead of

Change-Id: If9b8d1f32e58b32a9d9f8cd07aa10c30432e3183
Bug: 902904
Commit-Queue: Peng Huang <>
Reviewed-by: Antoine Labour <>
Cr-Commit-Position: refs/heads/master@{#614694}
18 files changed