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

printing/page_setup.cc

 // 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.
 
 #include "printing/page_setup.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 
@@ skipping 58 matching lines @@
   // I've seen this assert triggers on Canon GP160PF PCL 5e and HP LaserJet 5.
   // Since we don't know the dpi here, just disable the check.
   // DCHECK_LE(printable_area.bottom(), physical_size.height());
   DCHECK_GE(printable_area.x(), 0);
   DCHECK_GE(printable_area.y(), 0);
   DCHECK_GE(text_height, 0);
   physical_size_ = physical_size;
   printable_area_ = printable_area;
   text_height_ = text_height;
 
-  CalculateSizesWithinRect(printable_area_);
+  CalculateSizesWithinRect(printable_area_, text_height_);
 }
 
 void PageSetup::SetRequestedMargins(const PageMargins& requested_margins) {
   requested_margins_ = requested_margins;
   if (printable_area_.width() && printable_area_.height())
-    CalculateSizesWithinRect(printable_area_);
+    CalculateSizesWithinRect(printable_area_, text_height_);
 }
 
 void PageSetup::ForceRequestedMargins(const PageMargins& requested_margins) {
   requested_margins_ = requested_margins;
   if (physical_size_.width() && physical_size_.height())
-    CalculateSizesWithinRect(gfx::Rect(physical_size_));
+    CalculateSizesWithinRect(gfx::Rect(physical_size_), 0);
 }
 
 void PageSetup::FlipOrientation() {
   if (physical_size_.width() && physical_size_.height()) {
     gfx::Size new_size(physical_size_.height(), physical_size_.width());
     int new_y = physical_size_.width() -
                 (printable_area_.width() + printable_area_.x());
     gfx::Rect new_printable_area(printable_area_.y(),
                                  new_y,
                                  printable_area_.height(),
                                  printable_area_.width());
     Init(new_size, new_printable_area, text_height_);
   }
 }
 
-void PageSetup::CalculateSizesWithinRect(const gfx::Rect& bounds) {
+void PageSetup::CalculateSizesWithinRect(const gfx::Rect& bounds,
+                                         int text_height) {
   // Calculate the effective margins. The tricky part.
   effective_margins_.header = std::max(requested_margins_.header,
                                        bounds.y());
   effective_margins_.footer = std::max(requested_margins_.footer,
                                        physical_size_.height() -
                                            bounds.bottom());
   effective_margins_.left = std::max(requested_margins_.left,
                                      bounds.x());
   effective_margins_.top = std::max(std::max(requested_margins_.top,
                                              bounds.y()),
-                                    effective_margins_.header + text_height_);
+                                    effective_margins_.header + text_height);
   effective_margins_.right = std::max(requested_margins_.right,
                                       physical_size_.width() -
                                           bounds.right());
   effective_margins_.bottom =
       std::max(std::max(requested_margins_.bottom,
                         physical_size_.height() - bounds.bottom()),
-               effective_margins_.footer + text_height_);
+               effective_margins_.footer + text_height);
 
   // Calculate the overlay area. If the margins are excessive, the overlay_area
   // size will be (0, 0).
   overlay_area_.set_x(effective_margins_.left);
   overlay_area_.set_y(effective_margins_.header);
   overlay_area_.set_width(std::max(0,
                                    physical_size_.width() -
                                        effective_margins_.right -
                                        overlay_area_.x()));
   overlay_area_.set_height(std::max(0,
                                     physical_size_.height() -
                                         effective_margins_.footer -
                                         overlay_area_.y()));
 
   // Calculate the content area. If the margins are excessive, the content_area
   // size will be (0, 0).
   content_area_.set_x(effective_margins_.left);
   content_area_.set_y(effective_margins_.top);
   content_area_.set_width(std::max(0,
                                    physical_size_.width() -
                                        effective_margins_.right -
                                        content_area_.x()));
   content_area_.set_height(std::max(0,
                                     physical_size_.height() -
                                         effective_margins_.bottom -
                                         content_area_.y()));
 }
 
 }  // namespace printing