Fix print media page size by using the value we compute.

BUG=82472
TEST=NONE (in bug)


Review URL: http://codereview.chromium.org/8344016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@106160 0039d316-1c4b-4281-b951-d872f2087c98
PrintWebViewHelper::PrintPreviewContext::metafile() const {
  DCHECK(IsRendering());
  return metafile_.get();
}

PrintWebViewHelper::PrintPreviewContext::metafile() const {
  DCHECK(IsRendering());
  return metafile_.get();
}
