Disabling the test on windows 7.

CC'ing the original author of the test (According to git) since the test owners spreadsheet does not specify one for this test.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/770c9b3e4289390c2dfb43558f9f21eab96a5de0

commit 770c9b3e4289390c2dfb43558f9f21eab96a5de0
Author: robertocn <robertocn@chromium.org>
Date: Wed Mar 16 21:34:26 2016

Disabling blob_storage.blob_storage for windows.

TBR=sullivan
BUG= 595069 
CQ_EXTRA_TRYBOTS=tryserver.chromium.perf:android_s5_perf_cq;tryserver.chromium.perf:winx64_10_perf_cq;tryserver.chromium.perf:mac_retina_perf_cq;tryserver.chromium.perf:linux_perf_cq

Review URL: https://codereview.chromium.org/1801123003

Cr-Commit-Position: refs/heads/master@{#381550}

[modify] https://crrev.com/770c9b3e4289390c2dfb43558f9f21eab96a5de0/tools/perf/benchmarks/blob_storage.py

dmurph@, the blob_storage benchmark is now disabled on Windows -- the logs for the failures are now gone, but now there are no results on Windows 7 since 2015-07-16. https://chromeperf.appspot.com/report?sid=d302535281f59e8ac442afe957210100ca4098fc8de3db18a3f3eef630a31f8b&rev=381226

If we want to continue to get results for this test on Windows 7, we need to find out why it was failing and re-enable it.

Bisect job to try and reproduce the failure and possibly find a cause: https://build.chromium.org/p/tryserver.chromium.perf/builders/win_perf_bisect/builds/6503

Ah yeah we definitely want to re-enable these, they'll be moved to blink_perf though.