Fix crosperf generating duplicate key entries.

Fixes crosperf when reading data from cache.
Fix string find check for json file.

BUG: chromium:658875
TEST:crosperf unit tests
Change-Id: I34529102c29ed88efd848beb0363066f3b6e50f0
Reviewed-on: https://chrome-internal-review.googlesource.com/305910
Commit-Ready: Manoj Gupta <manojgupta@google.com>
Tested-by: Manoj Gupta <manojgupta@google.com>
Reviewed-by: Caroline Tice <cmtice@google.com>
1 file changed