Bump bleeding edge git to 1.9.5-chromium.6 build.

BUG=444470
R=scottmg@chromium.org, iannucci@google.com

Review URL: https://codereview.chromium.org/888923002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@293889 0039d316-1c4b-4281-b951-d872f2087c98

bootstrap/win/win_tools.bat

@@ -58,7 +58,7 @@ goto :END
 
 :GIT_CHECK
 if "%DEPOT_TOOLS_GIT_BLEEDING%" == "1" (
-  set GIT_VERSION=1.9.5.chromium.5
+  set GIT_VERSION=1.9.5.chromium.6
 ) else (
   set GIT_VERSION=1.9.5.chromium.5
 )