Fix grammatical errors in comments in ui/views

ui/views/controls/tree/tree_view_views_unittest.cc

Index: ui/views/controls/tree/tree_view_views_unittest.cc
diff --git a/ui/views/controls/tree/tree_view_views_unittest.cc b/ui/views/controls/tree/tree_view_views_unittest.cc
index b845ce860c8ea45516320bd990bbd3505c407ebd..43e3e1590a0a806caf0e58e5d7e59aedccdbd7f7 100644
--- a/ui/views/controls/tree/tree_view_views_unittest.cc
+++ b/ui/views/controls/tree/tree_view_views_unittest.cc
@@ -242,7 +242,7 @@ TEST_F(TreeViewViewsTest, TreeNodesRemoved) {
   EXPECT_EQ("root", GetSelectedNodeTitle());
   EXPECT_EQ(4, GetRowCount());
 
-  // Expand b1, then collapse it and remove it's only child, b1. This shouldn't
+  // Expand b1, then collapse it and remove its only child, b1. This shouldn't
   // effect the tree.
   tree_.Expand(GetNodeByTitle("b"));
   tree_.Collapse(GetNodeByTitle("b"));