Update Dr. Memory to r1955

TBR=zhaoqin@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/343713004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278252 0039d316-1c4b-4281-b951-d872f2087c98

third_party/drmemory/README.chromium

 Name: Dr. Memory
 Short Name: drmemory
 URL: http://code.google.com/p/drmemory
-Version: 1.7.1948
+Version: 1.7.1955
 License: LGPL 2.1
 License File: NOT_SHIPPED
 Security Critical: no

third_party/drmemory/drmemory-windows-sfx.exe.sha1

-dfde9e99e8f55ac911fdb8503c6f5f5b16534a96
\ No newline at end of file
+5a60dcc722ed7418a09e7068cf9b5f6188f0a24a
\ No newline at end of file