On Chrome OS, use the application locale to determine the default paper size rather than rely on GTK.

BUG=None.
TEST=Web pages printed from Chrome OS should use locale-specific default paper size (specifically, for US, it should use 8.5 x 11).

Review URL: http://codereview.chromium.org/5636001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68233 0039d316-1c4b-4281-b951-d872f2087c98

• chrome/browser/printing/print_job_worker.cc[diff]
• printing/emf_win_unittest.cc[diff]
• printing/printing_context.cc[diff]
• printing/printing_context.h[diff]
• printing/printing_context_cairo.cc[diff]
• printing/printing_context_cairo.h[diff]
• printing/printing_context_mac.h[diff]
• printing/printing_context_mac.mm[diff]
• printing/printing_context_win.cc[diff]
• printing/printing_context_win.h[diff]
• printing/printing_context_win_unittest.cc[diff]