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, 3 insertions, 4 deletions

diff --git a/cc/test/layer_tree_pixel_test.cc b/cc/test/layer_tree_pixel_test.cc
index 4e4e039..ed14e33 100644
--- a/cc/test/layer_tree_pixel_test.cc
+++ b/cc/test/layer_tree_pixel_test.cc
@@ -47,8 +47,7 @@ scoped_ptr<OutputSurface> LayerTreePixelTest::CreateOutputSurface(
       software_output_device->set_surface_expansion_size(
           surface_expansion_size);
       output_surface = make_scoped_ptr(
-          new PixelTestOutputSurface(
-              software_output_device.PassAs<SoftwareOutputDevice>()));
+          new PixelTestOutputSurface(software_output_device.Pass()));
       break;
     }
 
@@ -61,7 +60,7 @@ scoped_ptr<OutputSurface> LayerTreePixelTest::CreateOutputSurface(
   }
 
   output_surface->set_surface_expansion_size(surface_expansion_size);
-  return output_surface.PassAs<OutputSurface>();
+  return output_surface.Pass();
 }
 
 void LayerTreePixelTest::CommitCompleteOnThread(LayerTreeHostImpl* impl) {
@@ -229,7 +228,7 @@ scoped_ptr<SkBitmap> LayerTreePixelTest::CopyTextureMailboxToBitmap(
     const TextureMailbox& texture_mailbox) {
   DCHECK(texture_mailbox.IsTexture());
   if (!texture_mailbox.IsTexture())
-    return scoped_ptr<SkBitmap>();
+    return nullptr;
 
   scoped_ptr<gpu::GLInProcessContext> context = CreateTestInProcessContext();
   GLES2Interface* gl = context->GetImplementation();