For no margins, or printable area margins, don't factor in the header/footer size.

printing/page_setup.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PRINTING_PAGE_SETUP_H_
 #define PRINTING_PAGE_SETUP_H_
 
 #include "printing/printing_export.h"
 #include "ui/gfx/rect.h"
 
@@ skipping 47 matching lines @@
   const gfx::Size& physical_size() const { return physical_size_; }
   const gfx::Rect& overlay_area() const { return overlay_area_; }
   const gfx::Rect& content_area() const { return content_area_; }
   const gfx::Rect& printable_area() const { return printable_area_; }
   const PageMargins& effective_margins() const {
     return effective_margins_;
   }
 
  private:
   // Calculate overlay_area_, effective_margins_, and content_area_, based on
   // a constraint of |bounds|.

[dpapad, 2011/10/17 23:03:03]

Nit: Update comment.

[vandebo (ex-Chrome), 2011/10/17 23:16:54]

Done.

-  void CalculateSizesWithinRect(const gfx::Rect& bounds);
+  void CalculateSizesWithinRect(const gfx::Rect& bounds, int text_height);
 
   // Physical size of the page, including non-printable margins.
   gfx::Size physical_size_;
 
   // The printable area as specified by the printer driver. We can't get
   // larger than this.
   gfx::Rect printable_area_;
 
   // The printable area for headers and footers.
   gfx::Rect overlay_area_;
 
   // The printable area as selected by the user's margins.
   gfx::Rect content_area_;
 
   // Effective margins.
   PageMargins effective_margins_;
 
   // Requested margins.
   PageMargins requested_margins_;
 
   // Space that must be kept free for the overlays.
   int text_height_;
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_PAGE_SETUP_H_