Document that goog.net.XhrIo.getResponseJson throws Error if response is not JSON.
Document that goog.net.XhrIo.getResponseJson throws Error if response is not JSON.

RELNOTES: Document that goog.net.XhrIo.getResponseJson throws Error if response is not JSON.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=149018302

ikabirov/closure-library,teppeis/closure-library,ikabirov/closure-library,redforks/closure-library,teppeis/closure-library,lucidsoftware/closure-library,ikabirov/closure-library,platinumpixs/google-closure-library,platinumpixs/google-closure-library,platinumpixs/google-closure-library,teppeis/closure-library,redforks/closure-library,teppeis/closure-library,ikabirov/closure-library,lucidsoftware/closure-library,redforks/closure-library,google/closure-library,redforks/closure-library,lucidsoftware/closure-library,google/closure-library,lucidsoftware/closure-library,google/closure-library,platinumpixs/google-closure-library,google/closure-library,google/closure-library