ui/base/models: Use TreeNode::IsRoot in some obvious places.

Changes done here:
- Convert IsRoot to is_root (simple getter accessor).
- Add a simple unittest.

BUG=None
TEST=out/Debug/app_unittests --gtest_filter=TreeNodeModelTest.IsRoot

R=sky@chromium.org

Review URL: http://codereview.chromium.org/7104004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@87402 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 12 insertions, 3 deletions

diff --git a/ui/base/models/tree_node_model.h b/ui/base/models/tree_node_model.h
index a4509cf..254cd20 100644
--- a/ui/base/models/tree_node_model.h
+++ b/ui/base/models/tree_node_model.h
@@ -133,6 +133,9 @@ class TreeNode : public TreeModelNode {
   const NodeType* parent() const { return parent_; }
   NodeType* parent() { return parent_; }
 
+  // Returns true if this is the root node.
+  bool is_root() const { return parent_ == NULL; }
+
   // Returns the index of |node|, or -1 if |node| is not a child of this.
   int GetIndexOf(const NodeType* node) const {
     DCHECK(node);
@@ -149,9 +152,6 @@ class TreeNode : public TreeModelNode {
   // TreeModelNode:
   virtual const string16& GetTitle() const OVERRIDE { return title_; }
 
-  // Returns true if this is the root.
-  bool IsRoot() const { return parent_ == NULL; }
-
   // Returns true if this == ancestor, or one of this nodes parents is
   // ancestor.
   bool HasAncestor(const NodeType* ancestor) const {
diff --git a/ui/base/models/tree_node_model_unittest.cc b/ui/base/models/tree_node_model_unittest.cc
index acee7d0..b6097c3 100644
--- a/ui/base/models/tree_node_model_unittest.cc
+++ b/ui/base/models/tree_node_model_unittest.cc
@@ -317,4 +317,13 @@ TEST_F(TreeNodeModelTest, BasicOperations) {
   delete root;
 }
 
+TEST_F(TreeNodeModelTest, IsRoot) {
+  TreeNodeWithValue<int> root;
+  EXPECT_TRUE(root.is_root());
+
+  TreeNodeWithValue<int>* child1 = new TreeNodeWithValue<int>(1);
+  root.Add(child1, root.child_count());
+  EXPECT_FALSE(child1->is_root());
+}
+
 }  // namespace ui