The frontend was not taking into account the fact that some drivers do
not support program binaries.  The fix is that now

    glGetProgramiv(GL_PROGRAM_BINARY_LENGTH)

returns 0 under such circumstances.

Bug: angleproject:2780

Change-Id: I4ea2cda6bb4612e69dbd7e00b3d43b97ee3b3c3d
Reviewed-on: https://chromium-review.googlesource.com/1188768Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>