Fix the misalignment on CrOS of the tab background images

chrome/browser/ui/views/tabs/tab_strip.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/ui/views/tabs/tab_strip.h"
 
 #if defined(OS_WIN)
 #include <windowsx.h>
 #endif
 
 #include <algorithm>
 #include <iterator>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/view_ids.h"
 #include "chrome/browser/ui/views/tabs/stacked_tab_strip_layout.h"
 #include "chrome/browser/ui/views/tabs/tab.h"
 #include "chrome/browser/ui/views/tabs/tab_drag_controller.h"
+#include "chrome/browser/ui/views/tabs/tab_paint_util.h"
 #include "chrome/browser/ui/views/tabs/tab_strip_controller.h"
 #include "chrome/browser/ui/views/tabs/tab_strip_observer.h"
 #include "chrome/browser/ui/views/touch_uma/touch_uma.h"
 #include "content/public/browser/user_metrics.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/animation/animation_container.h"
 #include "ui/base/animation/throb_animation.h"
 #include "ui/base/default_theme_provider.h"
@@ skipping 370 matching lines @@
 
 bool NewTabButton::ShouldUseNativeFrame() const {
   return GetWidget() &&
     GetWidget()->GetTopLevelWidget()->ShouldUseNativeFrame();
 }
 
 gfx::ImageSkia NewTabButton::GetBackgroundImage(
     views::CustomButton::ButtonState state,
     ui::ScaleFactor scale_factor) const {
   int background_id = 0;
+  int background_overlay_id = 0;
   if (ShouldUseNativeFrame()) {
     background_id = IDR_THEME_TAB_BACKGROUND_V;
+    background_overlay_id = IDR_THEME_TAB_BACKGROUND_V_OVERLAY;
   } else if (tab_strip_->controller()->IsIncognito()) {
     background_id = IDR_THEME_TAB_BACKGROUND_INCOGNITO;
+    background_overlay_id = IDR_THEME_TAB_BACKGROUND_INCOGNITO_OVERLAY;
 #if defined(OS_WIN)
   } else if (win8::IsSingleWindowMetroMode()) {
     background_id = IDR_THEME_TAB_BACKGROUND_V;
+    background_overlay_id = IDR_THEME_TAB_BACKGROUND_V_OVERLAY;
 #endif
   } else {
     background_id = IDR_THEME_TAB_BACKGROUND;
+    background_overlay_id = IDR_THEME_TAB_BACKGROUND_OVERLAY;
   }
 
   int alpha = 0;
   switch (state) {
     case views::CustomButton::STATE_NORMAL:
     case views::CustomButton::STATE_HOVERED:
       alpha = ShouldUseNativeFrame() ? kNativeFrameInactiveTabAlpha : 255;
       break;
     case views::CustomButton::STATE_PRESSED:
       alpha = 145;
       break;
     default:
       NOTREACHED();
       break;
   }
 
   gfx::ImageSkia* mask =
       GetThemeProvider()->GetImageSkiaNamed(IDR_NEWTAB_BUTTON_MASK);
   int height = mask->height();
   int width = mask->width();
 
   // The canvas and mask has to use the same scale factor.
   if (!mask->HasRepresentation(scale_factor))
     scale_factor = ui::SCALE_FACTOR_100P;
 
   gfx::Canvas canvas(gfx::Size(width, height), scale_factor, false);
 
-  // For custom images the background starts at the top of the tab strip.
-  // Otherwise the background starts at the top of the frame.
-  gfx::ImageSkia* background =
-      GetThemeProvider()->GetImageSkiaNamed(background_id);
-  int offset_y = GetThemeProvider()->HasCustomImage(background_id) ?
-      0 : background_offset_.y();
+  // The new tab button is mirrored in RTL mode, but the button's background
+  // should never be mirrored.
+  if (base::i18n::IsRTL()) {
+    // Translate by |width| such that the same region is painted as if there was
+    // no flip.
+    canvas.Translate(gfx::Vector2d(width, 0));
+    canvas.Scale(-1, 1);
+  }
 
-  // The new tab background is mirrored in RTL mode, but the theme background
-  // should never be mirrored. Mirror it here to compensate.
-  float x_scale = 1.0f;
   int x = GetMirroredX() + background_offset_.x();
-  if (base::i18n::IsRTL()) {
-    x_scale = -1.0f;
-    // Offset by |width| such that the same region is painted as if there was no
-    // flip.
-    x += width;
-  }
-  canvas.TileImageInt(*background, x, newtab_button_v_offset() + offset_y,
-                      x_scale, 1.0f, 0, 0, width, height);
+  gfx::ImageSkia tiled_background = TabPaintUtil::CreateTiledInactiveBackground(
+      GetThemeProvider(), background_id, background_overlay_id,
+      background_offset_.y(), x, newtab_button_v_offset(), width, height);
+  canvas.DrawImageInt(tiled_background, 0, 0);
 
   if (alpha != 255) {
     SkPaint paint;
     paint.setColor(SkColorSetARGB(alpha, 255, 255, 255));
     paint.setXfermodeMode(SkXfermode::kDstIn_Mode);
     paint.setStyle(SkPaint::kFill_Style);
     canvas.DrawRect(gfx::Rect(0, 0, width, height), paint);
   }
 
   // White highlight on hover.
@@ skipping 2230 matching lines @@
   if (!adjust_layout_)
     return false;
 
 #if !defined(OS_CHROMEOS)
   if (ui::GetDisplayLayout() != ui::LAYOUT_TOUCH)
     return false;
 #endif
 
   return true;
 }