Fix the misalignment on CrOS of the tab background images

chrome/browser/ui/cocoa/themed_window.h

Index: chrome/browser/ui/cocoa/themed_window.h
diff --git a/chrome/browser/ui/cocoa/themed_window.h b/chrome/browser/ui/cocoa/themed_window.h
index 592e56722ae9d984e2bcc39d2e5553bbba4afd98..591521edef720fd86e4174adc19a72b01f047643 100644
--- a/chrome/browser/ui/cocoa/themed_window.h
+++ b/chrome/browser/ui/cocoa/themed_window.h
@@ -24,10 +24,11 @@ typedef NSUInteger ThemedWindowStyle;
 // Indicates how the theme image should be aligned.
 enum ThemeImageAlignment {
   // Aligns the top of the theme image with the top of the frame. Use this
-  // for IDR_THEME_THEME_FRAME.*
+  // for IDR_THEME_THEME_FRAME.* and IDR_THEME_TAB_BACKGROUND.
   THEME_IMAGE_ALIGN_WITH_FRAME,
   // Aligns the top of the theme image with the top of the tabs.
-  // Use this for IDR_THEME_TAB_BACKGROUND and IDR_THEME_TOOLBAR.
+  // Use this for IDR_THEME_TAB_BACKGROUND_OVERLAY,
+  // IDR_THEME_TAB_BACKGROUND_INACTIVE, and IDR_THEME_TOOLBAR.
   THEME_IMAGE_ALIGN_WITH_TAB_STRIP
 };