clang/win: Fix most -Wunused-function warnings in Chromium code.

printing/printed_document_win.cc

Index: printing/printed_document_win.cc
diff --git a/printing/printed_document_win.cc b/printing/printed_document_win.cc
index 3c6b7152ea1c0cd0c34ceedb59fa8d0b963366dd..ddba4ca48a6d362413fe5da96533f9317ded1875 100644
--- a/printing/printed_document_win.cc
+++ b/printing/printed_document_win.cc
@@ -25,10 +25,6 @@ void SimpleModifyWorldTransform(HDC context,
   DCHECK_NE(res, 0);
 }
 
-void DrawRect(HDC context, gfx::Rect rect) {
-  Rectangle(context, rect.x(), rect.y(), rect.right(), rect.bottom());
-}
-
 }  // namespace
 
 namespace printing {