Fix the misalignment on CrOS of the tab background images

chrome/browser/ui/gtk/tabs/tab_renderer_gtk.h

Index: chrome/browser/ui/gtk/tabs/tab_renderer_gtk.h
diff --git a/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.h b/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.h
index 0ab3baee479f8632fa554f1e216c2453e3dda388..f6313874b1e5f4278c4cf59cfa4df8439d2d3f3b 100644
--- a/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.h
+++ b/chrome/browser/ui/gtk/tabs/tab_renderer_gtk.h
@@ -313,13 +313,18 @@ class TabRendererGtk : public ui::AnimationDelegate,
   void PaintActiveTabBackground(GtkWidget* widget, cairo_t* cr);
   void PaintLoadingAnimation(GtkWidget* widget, cairo_t* cairo);
 
-  // Draws the given |tab_bg| onto |cr| using the tab shape masks along the
-  // sides for the rounded tab shape.
-  void DrawTabBackground(cairo_t* cr,
-                         GtkWidget* widget,
-                         const gfx::Image& tab_bg,
-                         int offset_x,
-                         int offset_y);
+  // Sets the tab background image as the source pattern within |cr|. |bounds|
+  // are the bounds of the source pattern which will be used.
+  // The tab background source pattern is generated based on whether the tab
+  // is active, whether the tab is in an incognito browser and on the current
+  // theme.
+  void SetTabBackgroundImageAsSource(cairo_t* cr,
+                                     GtkWidget* widget,
+                                     const gfx::Rect& bounds);
+
+  // Draws the tab background image onto |cr| using the tab shape masks along
+  // the sides for the rounded tab shape.
+  void DrawTabBackground(cairo_t* cr, GtkWidget* widget);
 
   // Draws the tab shadow using the given idr resources onto |cr|.
   void DrawTabShadow(cairo_t* cr,