Views a11y: Convert View's NativeViewAccessibility to a unique_ptr.

ui/views/accessibility/native_view_accessibility_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/accessibility/native_view_accessibility.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/gfx/geometry/rect_conversions.h"
@@ skipping 40 matching lines @@
     button_->AddChildView(label_);
     label_accessibility_ = NativeViewAccessibility::Create(label_);
 
     widget_->GetContentsView()->AddChildView(button_);
     widget_->Show();
   }
 
   void TearDown() override {
     if (!widget_->IsClosed())
       widget_->Close();
-    button_accessibility_->Destroy();
-    button_accessibility_ = NULL;
-    label_accessibility_->Destroy();
-    label_accessibility_ = NULL;
     ViewsTestBase::TearDown();
   }
 
  protected:
   views::Widget* widget_;
   TestButton* button_;
-  NativeViewAccessibility* button_accessibility_;
+  std::unique_ptr<NativeViewAccessibility> button_accessibility_;
   Label* label_;
-  NativeViewAccessibility* label_accessibility_;
+  std::unique_ptr<NativeViewAccessibility> label_accessibility_;
 };
 
 TEST_F(NativeViewAccessibilityTest, RoleShouldMatch) {
   EXPECT_EQ(ui::AX_ROLE_BUTTON, button_accessibility_->GetData().role);
   EXPECT_EQ(ui::AX_ROLE_STATIC_TEXT, label_accessibility_->GetData().role);
 }
 
 TEST_F(NativeViewAccessibilityTest, BoundsShouldMatch) {
   gfx::Rect bounds = gfx::ToEnclosingRect(
       button_accessibility_->GetData().location);
@@ skipping 136 matching lines @@
   // During the destruction of parent, OnBlur will be called and change the
   // visibility to false.
   parent->SetVisible(true);
   AXAuraObjCache* ax = AXAuraObjCache::GetInstance();
   ax->GetOrCreate(widget.get());
 }
 #endif
 
 }  // namespace test
 }  // namespace views