No, I'm afraid there is no portable way for performance counters in OpenGL ES 2.0. You will need to relay on the tools available for each vendor.
For OpenGLES 3.0 that family of functions have been added. Unfortunately, GL_TIME_ELAPSED is not a valid target for this version.
Please refer to section 2.13 Asynchronous Queries (3.02 April 8, 2013): http://www.khronos.org/registry/gles/specs/3.0/es_spec_3.0.2.pdf