Currently if the IMPLEMENTATION_COLOR_READ_FORMAT/TYPE context states are queried while the framebuffer is incomplete, INVALID_OPERATION is generated. https://github.com/KhronosGroup/WebGL/pull/2195 changed this rule to make it INVALID_FRAMEBUFFER_OPERATION. Chrome needs to implement this rule.

Further, once this is implemented, the top-of-tree conformance test conformance/extensions/oes-texture-half-float.html should be updated to require INVALID_FRAMEBUFFER_OPERATION, rather than allowing INVALID_OPERATION.