Fix grammatical errors in comments in ui/views

ui/views/window/dialog_delegate.h

Index: ui/views/window/dialog_delegate.h
diff --git a/ui/views/window/dialog_delegate.h b/ui/views/window/dialog_delegate.h
index 4ab4cd3606edd2fbc85563b7355abc36d99b3af2..28af3281cca46af692c84b7df0003e60c165cfc1 100644
--- a/ui/views/window/dialog_delegate.h
+++ b/ui/views/window/dialog_delegate.h
@@ -68,7 +68,7 @@ class VIEWS_EXPORT DialogDelegate : public WidgetDelegate {
   virtual View* GetExtraView();
 
   // Returns whether the height of the extra view should be at least as tall as
-  // the buttons. The default (false) is to give the extra view it's preferred
+  // the buttons. The default (false) is to give the extra view its preferred
   // height. By returning true the height becomes
   // max(extra_view preferred height, buttons preferred height).
   virtual bool GetSizeExtraViewHeightToButtons();