Cleanup various bits of printing code.

Review URL: https://codereview.chromium.org/27146002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228518 0039d316-1c4b-4281-b951-d872f2087c98
cc: Enable PageScaleImplSidePaintingPerfTest.HeavyPage

This test is no longer as noisy as it was when it was diabled.

BUG=301964

Review URL: https://codereview.chromium.org/27225002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228519 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228518
SVN changes up to revision 228519