Makes Background only create a brush when needed. This avoids

views/background.h

Index: views/background.h
diff --git a/views/background.h b/views/background.h
index 56bb7f8f1b554fbc4f02517e9bb8a086a19a25b7..41126c4694529d0cd2145020a3622685dc41058f 100644
--- a/views/background.h
+++ b/views/background.h
@@ -84,14 +84,14 @@ class Background {
   // TODO(port): Make GetNativeControlBrush portable (currently uses HBRUSH).
 
   // Get the brush that was specified by SetNativeControlColor
-  HBRUSH GetNativeControlBrush() const { return native_control_brush_; };
+  HBRUSH GetNativeControlBrush() const;
 #endif  // defined(OS_WIN)
 
  private:
   SkColor color_;
 #if defined(OS_WIN)
   // TODO(port): Create portable replacement for HBRUSH.
-  HBRUSH native_control_brush_;
+  mutable HBRUSH native_control_brush_;
 #endif  // defined(OS_WIN)
 
   DISALLOW_COPY_AND_ASSIGN(Background);