[Clean up] Fix old name of metrics action as it's now a histogram.
[Clean up] Fix old name of metrics action as it's now a histogram.

R=estade@chromium.org
TEST=This is The Right Thing To Do™
BUG=None


Review URL: http://codereview.chromium.org/9429059

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@123223 0039d316-1c4b-4281-b951-d872f2087c98

gavinp/chromium,gavinp/chromium,adobe/chromium,adobe/chromium,ropik/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,gavinp/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,yitian134/chromium,gavinp/chromium,ropik/chromium,ropik/chromium,gavinp/chromium,adobe/chromium,yitian134/chromium,ropik/chromium,adobe/chromium,ropik/chromium,gavinp/chromium,gavinp/chromium,yitian134/chromium,ropik/chromium,yitian134/chromium,ropik/chromium,gavinp/chromium,gavinp/chromium,adobe/chromium,gavinp/chromium,ropik/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,yitian134/chromium