GitLab

Switched to returning std::string instead of base::StringPiece in GetScaleFactorsAsString() as base::StringPiece does not take ownership of data passed to it in the constructor.

TBR=sky

Review URL: https://chromiumcodereview.appspot.com/10854003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150058 0039d316-1c4b-4281-b951-d872f2087c98