cc:: Use clip tree instead of layer tree during hit testing

cc/trees/layer_tree_impl_unittest.cc

Index: cc/trees/layer_tree_impl_unittest.cc
diff --git a/cc/trees/layer_tree_impl_unittest.cc b/cc/trees/layer_tree_impl_unittest.cc
index b6cf7f23148086434762b7d1c74c644493137d9c..42b34b9e84848a6faa54855618c99620da155f7e 100644
--- a/cc/trees/layer_tree_impl_unittest.cc
+++ b/cc/trees/layer_tree_impl_unittest.cc
@@ -380,6 +380,74 @@ TEST_F(LayerTreeImplTest, HitTestingForSingleRotatedLayer) {
   ASSERT_FALSE(result_layer);
 }
 
+TEST_F(LayerTreeImplTest, HitTestingSiblings) {
+  // This tests hit testing when the test point hits only one of the siblings.
+  gfx::Transform identity_matrix;
+  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
+  SetLayerPropertiesForTesting(root.get(), identity_matrix, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(100, 100), true, false,
+                               true);
+  scoped_ptr<LayerImpl> child1 =
+      LayerImpl::Create(host_impl().active_tree(), 2);
+  SetLayerPropertiesForTesting(child1.get(), identity_matrix, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(25, 25), true, false,
+                               false);
+  child1->SetMasksToBounds(true);
+  child1->SetDrawsContent(true);
+  scoped_ptr<LayerImpl> child2 =
+      LayerImpl::Create(host_impl().active_tree(), 3);
+  SetLayerPropertiesForTesting(child2.get(), identity_matrix, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(75, 75), true, false,
+                               false);
+  child2->SetMasksToBounds(true);
+  child2->SetDrawsContent(true);
+  root->AddChild(std::move(child1));
+  root->AddChild(std::move(child2));
+
+  host_impl().SetViewportSize(root->bounds());
+  host_impl().active_tree()->SetRootLayer(std::move(root));
+  host_impl().UpdateNumChildrenAndDrawPropertiesForActiveTree();
+
+  gfx::PointF test_point(50.f, 50.f);
+  LayerImpl* result_layer =
+      host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
+  ASSERT_TRUE(result_layer);
+  EXPECT_EQ(3, result_layer->id());
+}
+
+TEST_F(LayerTreeImplTest, HitTestingPointOutsideMaxTextureSize) {
+  gfx::Transform identity_matrix;
+  int max_texture_size =
+      host_impl().active_tree()->resource_provider()->max_texture_size();
+  gfx::Size bounds(max_texture_size + 100, max_texture_size + 100);
+
+  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
+  SetLayerPropertiesForTesting(root.get(), identity_matrix, gfx::Point3F(),
+                               gfx::PointF(), bounds, true, false, true);
+
+  scoped_ptr<LayerImpl> surface =
+      LayerImpl::Create(host_impl().active_tree(), 2);
+  SetLayerPropertiesForTesting(surface.get(), identity_matrix, gfx::Point3F(),
+                               gfx::PointF(), bounds, true, false, true);
+  surface->SetMasksToBounds(true);
+  surface->SetDrawsContent(true);
+
+  root->AddChild(std::move(surface));
+  host_impl().SetViewportSize(root->bounds());
+  host_impl().active_tree()->SetRootLayer(std::move(root));
+  host_impl().UpdateNumChildrenAndDrawPropertiesForActiveTree();
+
+  gfx::PointF test_point(max_texture_size - 50, max_texture_size - 50);
+  LayerImpl* result_layer =
+      host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
+  ASSERT_TRUE(result_layer);

[ajuma, 2016/01/06 14:18:55]

EXPECT_TRUE
(it would make sense to use ASSERT if you were next going to dereference
result_layer and prefered to crash at the assert rather later when result_layer
is null, but in this case we're not using result_layer)

[jaydasika, 2016/01/06 19:31:20]

Done.

+
+  test_point = gfx::PointF(max_texture_size + 50, max_texture_size + 50);
+  result_layer =
+      host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
+  ASSERT_FALSE(result_layer);

[ajuma, 2016/01/06 14:18:55]

EXPECT_FALSE

[jaydasika, 2016/01/06 19:31:20]

Done.

+}
+
 TEST_F(LayerTreeImplTest, HitTestingForSinglePerspectiveLayer) {
   scoped_ptr<LayerImpl> root =
       LayerImpl::Create(host_impl().active_tree(), 12345);