[ObjC ARC] Converts ios/chrome/browser/ui/toolbar:unit_tests to ARC.

ios/chrome/browser/ui/toolbar/toolbar_controller_unittest.mm

Index: ios/chrome/browser/ui/toolbar/toolbar_controller_unittest.mm
diff --git a/ios/chrome/browser/ui/toolbar/toolbar_controller_unittest.mm b/ios/chrome/browser/ui/toolbar/toolbar_controller_unittest.mm
index 1e7fe9533b8a7fffc9b205323950c4cbf016fdbf..34ec16e52941a7425e96f1b59db49570cedff8bf 100644
--- a/ios/chrome/browser/ui/toolbar/toolbar_controller_unittest.mm
+++ b/ios/chrome/browser/ui/toolbar/toolbar_controller_unittest.mm
@@ -5,13 +5,16 @@
 #import <Foundation/Foundation.h>
 
 #include "base/format_macros.h"
-#include "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/ui/toolbar/toolbar_controller.h"
 #import "ios/chrome/browser/ui/toolbar/toolbar_controller_private.h"
 #import "ios/chrome/browser/ui/ui_util.h"
 #include "testing/gtest_mac.h"
 #include "testing/platform_test.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 // A constant holding some number of tabs that will trigger an easter egg.
 const NSInteger kStackButtonEasterEggTabCount = kStackButtonMaxTabCount + 1;
 
@@ -31,11 +34,11 @@ namespace {
 class ToolbarControllerTest : public PlatformTest {
  protected:
   void SetUp() override {

[sdefresne, 2017/04/27 13:40:58]

Please add the missing call to PlatformTest::SetUp here:

  void SetUp() override {
    PlatformTest::SetUp();
    ....
  }

[gambard, 2017/04/27 14:58:22]

Done.

-    toolbarController_.reset([[ToolbarController alloc]
-        initWithStyle:ToolbarControllerStyleLightMode]);
+    toolbarController_ = [[ToolbarController alloc]
+        initWithStyle:ToolbarControllerStyleLightMode];
   }
 
-  base::scoped_nsobject<ToolbarController> toolbarController_;
+  ToolbarController* toolbarController_;
 };
 
 // Verify that if tab count is set to zero, the title is blank, but the a11y