cc: Remove use of PassAs() and constructor-casting with scoped_ptr.

Say you have class A and subclass B.

Previously it was required to PassAs() a scoped_ptr<B> into a
scoped_ptr<A>. This is no longer needed, so just use Pass(). For newly
created scoped_ptrs, you can just use make_scoped_ptr always now.

And when you want to return or assign an empty scoped_ptr(), you can
now use nullptr directly.

Also adds PRESUBMIT checks for:
- return scoped<T>(foo). This should be return make_scoped_ptr(foo).
- bar = scoped<T>(foo). This should be return bar = make_scoped_ptr(foo).
- return scoped<T>(). This should be return nullptr.
- bar = scoped<T>(). This should be return bar = nullptr.

This also replaces p.reset() with p = nullptr; But it does not add a
PRESUBMIT check for that because there are things other than scoped_ptr
with a reset() function.

R=enne@chromium.org

Committed: https://crrev.com/7bb3dbede19d87f0338797756ffd738adc6bca08
Cr-Commit-Position: refs/heads/master@{#297096}

Review URL: https://codereview.chromium.org/609663003

Cr-Commit-Position: refs/heads/master@{#297121}

1 files changed, 2 insertions, 3 deletions

diff --git a/cc/trees/layer_tree_impl_unittest.cc b/cc/trees/layer_tree_impl_unittest.cc
index a0dd11a..7fc1645 100644
--- a/cc/trees/layer_tree_impl_unittest.cc
+++ b/cc/trees/layer_tree_impl_unittest.cc
@@ -25,8 +25,7 @@ class LayerTreeImplTest : public LayerTreeHostCommonTest {
     settings.layer_transforms_should_scale_layer_contents = true;
     host_impl_.reset(
         new FakeLayerTreeHostImpl(settings, &proxy_, &shared_bitmap_manager_));
-    EXPECT_TRUE(host_impl_->InitializeRenderer(
-        FakeOutputSurface::Create3d().PassAs<OutputSurface>()));
+    EXPECT_TRUE(host_impl_->InitializeRenderer(FakeOutputSurface::Create3d()));
   }
 
   FakeLayerTreeHostImpl& host_impl() { return *host_impl_; }
@@ -124,7 +123,7 @@ TEST_F(LayerTreeImplTest, HitTestingForSingleLayerAndHud) {
   hud->SetDrawsContent(true);
 
   host_impl().active_tree()->set_hud_layer(hud.get());
-  root->AddChild(hud.PassAs<LayerImpl>());
+  root->AddChild(hud.Pass());
 
   host_impl().SetViewportSize(hud_bounds);
   host_impl().active_tree()->SetRootLayer(root.Pass());