Combine tab background image getter code into one place.

chrome/browser/ui/views/tabs/tab.h

Index: chrome/browser/ui/views/tabs/tab.h
diff --git a/chrome/browser/ui/views/tabs/tab.h b/chrome/browser/ui/views/tabs/tab.h
index 82610738ae87ab2c256b897231f21bf4d3454df4..38ea62c04d85f5750dd043a9817fa767d043887c 100644
--- a/chrome/browser/ui/views/tabs/tab.h
+++ b/chrome/browser/ui/views/tabs/tab.h
@@ -298,11 +298,6 @@ class Tab : public gfx::AnimationDelegate,
   // Returns the rectangle for the light bar in immersive mode.
   gfx::Rect GetImmersiveBarRect() const;
 
-  // Gets the tab id and frame id.
-  void GetTabIdAndFrameId(views::Widget* widget,
-                          int* tab_id,
-                          int* frame_id) const;
-
   // Performs a one-time initialization of static resources such as tab images.
   static void InitTabResources();