vrend,blitter: Sync when switching context.
When switching context, if we want to use shared objects from previous context, we need to insert glWaitSync to make sure the GL commands are executed in sequences. This fixes 8 dEQP tests on mali:
dEQP-GLES2.functional.texture.mipmap.2d.generate.a8_fastest dEQP-GLES2.functional.texture.mipmap.2d.generate.a8_nicest dEQP-GLES2.functional.texture.mipmap.cube.generate.a8_fastest dEQP-GLES2.functional.texture.mipmap.cube.generate.a8_nicest dEQP-GLES2.functional.texture.specification.basic_copyteximage2d.2d_rgb dEQP-GLES2.functional.texture.specification.basic_copyteximage2d.cube_rgb dEQP-GLES2.functional.texture.specification.basic_copytexsubimage2d.2d_rgb dEQP-GLES2.functional.texture.specification.basic_copytexsubimage2d.cube_rgb
Signed-off-by: Lepton Wu lepton@chromium.org