GTK: Move to gtk_widget_get_allocation() for some of chrome/browser/ui/gtk/

chrome/browser/ui/gtk/custom_button.h

Index: chrome/browser/ui/gtk/custom_button.h
diff --git a/chrome/browser/ui/gtk/custom_button.h b/chrome/browser/ui/gtk/custom_button.h
index 4fb749c7293f84c8b64897cd44ae6b011c726d70..15d837e2c06d5d575962c4ed8b5cd26dde338864 100644
--- a/chrome/browser/ui/gtk/custom_button.h
+++ b/chrome/browser/ui/gtk/custom_button.h
@@ -169,15 +169,8 @@ class CustomDrawButton : public content::NotificationObserver {
 
   GtkWidget* widget() const { return widget_.get(); }
 
-  gfx::Rect bounds() const {
-      return gfx::Rect(widget_->allocation.x,
-                       widget_->allocation.y,
-                       widget_->allocation.width,
-                       widget_->allocation.height);
-  }
-
-  int width() const { return widget_->allocation.width; }
-  int height() const { return widget_->allocation.height; }
+  // Returns the width of the widget's allocation.
+  int WidgetWidth() const;
 
   // Returns the dimensions of the first surface.
   int SurfaceWidth() const;