Avoids some asserts with ToT WebKit by using valid layers. Using all empty layers or resetting the root layer unnecessarily was causing problems.

BUG=None
TEST=compositor_unittest

Review URL: http://codereview.chromium.org/8561014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@110935 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 18 insertions, 14 deletions

diff --git a/ui/gfx/compositor/compositor.cc b/ui/gfx/compositor/compositor.cc
index 485dc2d..97508f3 100644
--- a/ui/gfx/compositor/compositor.cc
+++ b/ui/gfx/compositor/compositor.cc
@@ -35,6 +35,8 @@ void Compositor::ScheduleDraw() {
 }
 
 void Compositor::SetRootLayer(Layer* root_layer) {
+  if (root_layer_ == root_layer)
+    return;
   if (root_layer_)
     root_layer_->SetCompositor(NULL);
   root_layer_ = root_layer;
diff --git a/ui/gfx/compositor/layer_unittest.cc b/ui/gfx/compositor/layer_unittest.cc
index c8a609f..d9203ad 100644
--- a/ui/gfx/compositor/layer_unittest.cc
+++ b/ui/gfx/compositor/layer_unittest.cc
@@ -1119,27 +1119,29 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_DrawPixels) {
 // Checks the logic around Compositor::SetRootLayer and Layer::SetCompositor.
 TEST_F(LayerWithRealCompositorTest, MAYBE_SetRootLayer) {
   Compositor* compositor = GetCompositor();
-  Layer l1;
-  EXPECT_EQ(NULL, l1.GetCompositor());
+  scoped_ptr<Layer> l1(CreateColorLayer(SK_ColorRED,
+                                        gfx::Rect(20, 20, 400, 400)));
+  scoped_ptr<Layer> l2(CreateColorLayer(SK_ColorBLUE,
+                                        gfx::Rect(10, 10, 350, 350)));
 
-  Layer l2;
-  EXPECT_EQ(NULL, l2.GetCompositor());
+  EXPECT_EQ(NULL, l1->GetCompositor());
+  EXPECT_EQ(NULL, l2->GetCompositor());
 
-  compositor->SetRootLayer(&l1);
-  EXPECT_EQ(compositor, l1.GetCompositor());
+  compositor->SetRootLayer(l1.get());
+  EXPECT_EQ(compositor, l1->GetCompositor());
 
-  l1.Add(&l2);
-  EXPECT_EQ(compositor, l2.GetCompositor());
+  l1->Add(l2.get());
+  EXPECT_EQ(compositor, l2->GetCompositor());
 
-  l1.Remove(&l2);
-  EXPECT_EQ(NULL, l2.GetCompositor());
+  l1->Remove(l2.get());
+  EXPECT_EQ(NULL, l2->GetCompositor());
 
-  l1.Add(&l2);
-  EXPECT_EQ(compositor, l2.GetCompositor());
+  l1->Add(l2.get());
+  EXPECT_EQ(compositor, l2->GetCompositor());
 
   compositor->SetRootLayer(NULL);
-  EXPECT_EQ(NULL, l1.GetCompositor());
-  EXPECT_EQ(NULL, l2.GetCompositor());
+  EXPECT_EQ(NULL, l1->GetCompositor());
+  EXPECT_EQ(NULL, l2->GetCompositor());
 }
 
 // Checks that compositor observers are notified when: