retry r123804 - ntp theme fixes

chrome/browser/ntp_background_util.cc

 // Copyright (c) 2012 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 "chrome/browser/ntp_background_util.h"
 
+#include <cmath>
+
 #include "base/logging.h"
 #include "chrome/browser/themes/theme_service.h"
 #include "grit/theme_resources.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/skia_util.h"
 
 namespace {
 
 void PaintThemeBackground(
     gfx::Canvas* canvas, SkBitmap* ntp_background, int tiling, int alignment,
     const gfx::Rect& area, int tab_contents_height) {
   int x_pos = 0;
   int y_pos = 0;
   int width = area.width() + ntp_background->width();
   int height = area.height() + ntp_background->height();
 
-  if (alignment & ThemeService::ALIGN_BOTTOM)
+  if (alignment & ThemeService::ALIGN_BOTTOM) {
     y_pos += area.height() + tab_contents_height - ntp_background->height();
+  } else if (alignment & ThemeService::ALIGN_TOP) {
+    // no op
+  } else {  // ALIGN_CENTER
+    y_pos += std::floor(area.height() + tab_contents_height / 2.0 -
+        ntp_background->height() / 2.0 + 0.5);
+  }
 
   if (alignment & ThemeService::ALIGN_RIGHT) {
     x_pos += area.width() - ntp_background->width();
   } else if (alignment & ThemeService::ALIGN_LEFT) {
     // no op
   } else {  // ALIGN_CENTER
-    x_pos += area.width() / 2 - ntp_background->width() / 2;
+    x_pos +=
+        std::floor(area.width() / 2.0 - ntp_background->width() / 2.0 + 0.5);
   }
 
   if (tiling != ThemeService::REPEAT &&
       tiling != ThemeService::REPEAT_X) {
     width = ntp_background->width();
   } else if (x_pos > 0) {
     x_pos = x_pos % ntp_background->width() - ntp_background->width();
   }
 
   if (tiling != ThemeService::REPEAT &&
@@ skipping 17 matching lines @@
                                                     const gfx::Rect& area,
                                                     int tab_contents_height) {
   // Draw the background to match the new tab page.
   canvas->FillRect(area, tp->GetColor(ThemeService::COLOR_NTP_BACKGROUND));
 
   if (tp->HasCustomImage(IDR_THEME_NTP_BACKGROUND)) {
     int tiling = ThemeService::NO_REPEAT;
     tp->GetDisplayProperty(ThemeService::NTP_BACKGROUND_TILING, &tiling);
     int alignment;
     if (tp->GetDisplayProperty(ThemeService::NTP_BACKGROUND_ALIGNMENT,
-        &alignment)) {
+                               &alignment)) {
       SkBitmap* ntp_background = tp->GetBitmapNamed(IDR_THEME_NTP_BACKGROUND);
 
       PaintThemeBackground(
           canvas, ntp_background, tiling, alignment, area, tab_contents_height);
     }
   }
 }